Invasive Native Minnow found in NH

In fact it is a common occurrence, and certainly far more common for a few fish to be transported unnoticed.

Rains of fish certainly do happen, but they are much rarer than you suggest.

Take a look at this thread. http://forum.nanfa.o...h__1#entry73111

The example you cited from Australia is very clearly not a rain of fish and there are many impediments to a rain of fish transporting fish very far, and having them survive and recruit.

Cheers
Peter

Yes, that thread was about the same time as the event. But when you call it rare what are the odds that if it does happen there are going to be enough fish to notice? Or in an area where even large numbers are going to be noticed? In fact at least one fish could fall with ever rain and never be noticed. If you have a body of water of size X devoid of fish, how long does it take on average to acquire fish on its own? I know the cow ponds dug in east Texas get fish pretty quickly after being created without being stocked. To think that relatively rare rains containing noticeably large numbers of fish can occur without an unnoticeably few fish falling with rains being orders of magnitude more common is tantamount to assuming the occurrence is of supernatural origin. You would have to have some experiments with unreasonably tight controls to to push me anywhere close to that direction.

As far as the rareness is concerned, there are places like Yoro Honduras which has a festival called Lluvia de Peces (Rain of Fishes) yearly, as these fish rains have occurred yearly for over a century and these people collect them to eat. Many of the fish are in fact alive and obviously of effective eating size. So how much of this presumed rareness is simply a rareness in noticeable numbers of fair sized fish remains an open question. What of fry falling, which are so small they can swim in a rain drop? Some weather events have even been reported to empty the water out of ponds.

If you study the phenomena the waterspout theory is good as far as it goes but remains highly problematic. Take the mentioned Australian case last year. The rain that dropped these fish developed locally, yet the partly live fish it dropped was not from any region the storm development took place in.

Personally, I suspect a non-linear atmospheric phenomena roughly similar to rogue waves in the ocean. Like what was rejected until one hit an oil rig and we got detailed measurements of its characteristics. We have subsequently explained these rogue wave, but standard wave mechanics do not apply. The wave mechanics that do apply is somewhat more akin to waves in quantum mechanics than standard wave mechanics. No, no goofy existential implications are implied. If this is so then it only makes sense that certain geographical regions with seasonal atmospheric dynamics over such geography would result in more events. Which appears supported by the recurring instances in some areas. Yet you would still expect a few stragglers to drop between the pickup and dropping locations.

The fact is this phenomena has always been relegated to the X-files department, even when accepted as observationally valid. No effective measurements of even the observed large scale drops have been taken. Much less measurements of the low intensity small scale drops that go unnoticed. I am a skeptic myself, but the skeptics minimalist approach to explanation defines the failures of claims made on insufficient data, not an authoritative explanation in itself. For that we need more measurements and data.

Meanwhile, these low intensity fish drops likely plays a highly significant role in the distribution of otherwise geographically locked species. One thing I will put money on, dig yourself a fenced off pond in east Texas today. By the end of the summer you will have fish in it. Birds perhaps? Perhaps a better approach would be do build a series of big funnels, or use the roof of a house with a slick surface as a funnel trap. These measurements are needed to access the ecological consequences. Until some effective measurements are obtained both side of any debate are crippled by a lack of empirical data. So the claim of rareness remains just that while presuming large scale observable fish drops is the real and total extent of the phenomena.

I know the cow ponds dug in east Texas get fish pretty quickly after being created without being stocked.

Those don't get inhabited due to rains of fish, the fish swim there. We massively underestimate the ability of fish to swim during large rainfall events.

As far as the rareness is concerned, there are places like Yoro Honduras which has a festival called Lluvia de Peces (Rain of Fishes) yearly, as these fish rains have occurred yearly for over a century and these people collect them to eat. Many of the fish are in fact alive and obviously of effective eating size. So how much of this presumed rareness is simply a rareness in noticeable numbers of fair sized fish remains an open question.

The fact that it happens annually make it seem rather like a biological phenomenon rather than a rain of fish. I've never seen any clear account of the Honduras thing in terms of what species are involved, or really any details beyond the brief blurb on wikipedia. http://en.wikipedia....Lluvia_de_Peces It does sound interesting though!

The rain that dropped these fish developed locally, yet the partly live fish it dropped was not from any region the storm development took place in.

The rain didn't drop the fish, they swum there.

The fact is this phenomena has always been relegated to the X-files department, even when accepted as observationally valid.

That's a good way to put it. It is a real phenomenon, but it is much rarer than people suppose and there are many issues that any fish flying through the air would need to deal with in order to survive. As someone commented during another discussion on this topic was that any time they dropped a fish 3ft in their hatchery it usually ended up dying. http://forums.angfa....highlight=rains

Ultimately, extraordinary events require extraordinary evidence that they happened.

Cheers
Peter

Those don't get inhabited due to rains of fish, the fish swim there. We massively underestimate the ability of fish to swim during large rainfall events.

Even if the "swimming there" hypothesis is correct, the notion that large noticeable fish drops in rain are not orders of magnitude less common than an un-noticeably few small fish dropping is as absurd as a supernatural explanation in itself. Unless, which apparently neither of us do, suppose that raining fish simply does not occur at all and that all reports are fully explained by terrestrial events.

In the particular pond we dug by hand it had embankments on all sides. In fact we intentionally built the embankment to increase the potential depth of the duck pond. The nearest creak was approximate 2 miles away and the nearest pond approximately one mile away. The other pond being across a highway with no drainage connections at all, wrong slops. The creak might technically form part of the drainage area of the duck pond, but across two miles of wooded area I constantly explored even during heavy rains in spite of parents objections, and no effective connecting drainage occurred even discounting the embankments around the pond. By whatever method they were transported it was not by swimming there. Even roadside drainage, which could have potentially carried fish from even more distant bridges, was diverted well around anything approaching the property the pond was on. This of course does not prove, even to me alone, the source was fish rain.

The fact that it happens annually make it seem rather like a biological phenomenon rather than a rain of fish. I've never seen any clear account of the Honduras thing in terms of what species are involved, or really any details beyond the brief blurb on wikipedia. http://en.wikipedia....Lluvia_de_Peces It does sound interesting though!

It is worth being skeptical of any particular case, as most such cases are not the result of falling from the sky as the reports imply. Especially when no systematic efforts are made to justify any given reports. Reminds me of the way my family would laugh when I would leave the supper table to go see what they were debating about. I very much want better systematic observations of these events, on all scales.

Although a National Geographic team actually witnessed this event in the 70s, no confirmation they actually came from the sky was provided. However, it was stated that the fish are not local to the area. National Geographic never actually published any reports of this expedition on the record, only some general statements by the participants. It does seem likely these fish are subterranean though. The lack of information or even concern for real information is mindboggling.

The rain didn't drop the fish, they swum there.

I have never witnessed fish raining, but I have seen fish in cow watering troughs well off the ground. Notably the area of Texas I am most familiar with is a high tornado area. I do suspect many or most cases of animal rains do not involve animals actually coming out of the sky. Yet there is also cases of animal parts, frozen animals even sometimes encased in ice. These certainly did not swim there. So however many cases this claim may be valid for, it certainly does not address the problem. Nor does it address how many orders of magnitude more likely it is for a few fish to be transported this way than a large scale high number animal rain event which is observed. So to say they 'swam' there is invalid regardless of how often it is correct.

That's a good way to put it. It is a real phenomenon, but it is much rarer than people suppose and there are many issues that any fish flying through the air would need to deal with in order to survive. As someone commented during another discussion on this topic was that any time they dropped a fish 3ft in their hatchery it usually ended up dying. http://forums.angfa....highlight=rains

Ultimately, extraordinary events require extraordinary evidence that they happened.

Cheers
Peter

But we already 'know' it is a real phenomena, hence that such events occur requires no further evidence whatsoever. What we do not know is the extent of the phenomena. To reject that a known phenomena lacking any direct study lacks any extent beyond 'to obscure to be concerned about' is tantamount to denying that events known to happen do not happen without being observed. It also denies the essentially unavoidable reality that the numbers of events involving an unnoticeable few specimens trumps by many orders of magnitude the number of events involving noticeably large numbers of organisms.

So my point is, rather than assign obscurity to pre-established phenomena lacking any empirical measure of obscurity, we need actual data on how obscure the phenomena is. This data is not impossible to get, but certainly requires more than hand waving it away as obscure. I am far more interested in the total ecological exchange rate than I am in big fish falling from the sky in great numbers for people to philosophically babble over. The obscurity claim is just as empirically vacuous as the reports of animal rain in most cases.

In the particular pond we dug by hand it had embankments on all sides. In fact we intentionally built the embankment to increase the potential depth of the duck pond. The nearest creak was approximate 2 miles away and the nearest pond approximately one mile away. The other pond being across a highway with no drainage connections at all, wrong slops. The creak might technically form part of the drainage area of the duck pond, but across two miles of wooded area I constantly explored even during heavy rains in spite of parents objections, and no effective connecting drainage occurred even discounting the embankments around the pond.

During exceptional rain bursts just about everything on the terrestrial landscape could be potentially crossed by fish (unless you are in steep topography). Not all species, but certainly some. As I said, we massively underestimate the ability of fish to cross "land".

I have never witnessed fish raining, but I have seen fish in cow watering troughs well off the ground. Notably the area of Texas I am most familiar with is a high tornado area.

Do you really think that most fish could survive being carried by a tornado? At some point earlier you mentioned fry in rain drops. I'm not sure if you have ever tried to move fry from one container to another, but at least in many species it is very difficult to do it when being extremely gentle.

But we already 'know' it is a real phenomena, hence that such events occur requires no further evidence whatsoever.

If someone wishes to claim that fish flopping around on the ground was due to a rain of fish then they'd better have more evidence than that to support it! That is my entire point. I'm not saying rains of fish do not happen, but often when such claims are made there is no evidence to support it.

In Australia virtually everyone in the country outside of big cities have water tanks fed by their roofs. Thus if it rains fish, then fish will be in their water tanks. Everyone that I have spoken to who claimed to have witnessed a rain of fish (most people in the outback do think they have seen rains of fish) had never found one in their roof or in the water tank.

So my point is, rather than assign obscurity to pre-established phenomena lacking any empirical measure of obscurity, we need actual data on how obscure the phenomena is. This data is not impossible to get, but certainly requires more than hand waving it away as obscure.

An established phenomenon that based on everything we know and understand is quite rare, thus using such a rare event to explain an unrare event (new fish showing up in a farm pond, or in a new drainage where people fish) is not very likely to be the correct explanation. It could be, but it is pretty unlikely.

Cheers
Peter

Hey, these roof fed water tanks in Australia might be worth looking closer at. You do have a very serious and valid point with respect to these reports of raining fish lacking any objective value. It is highly aggravating how even those who want to present themselves as authoritative will dance around actual evidence. To this you are dead on. Neither is the outside possibility of a natural event grounds for overlooking more likely and more common irresponsible behavior by people. These points should not be controversial, and no part of my attempts to justify the call for more actual data on this should detract from those concerns.

However, if two valid major fish rain events occur worldwide a year, as I have seen claimed without qualification, then the transport of a few specimens per year in the US is well within reason. Thus it is also reasonable that ever decade or so we will see instances similar to the rosyside dace. Most of which will fail to form a new population. How likely is this really? Nobody has a clue. Certainly far less likely than irresponsible people, but that really says nothing about how likely it is.

The 'splat' objection to raining fish living does not really hold up either. Even the presumably more unusual larger fish can survive this. The highest freefall survived by a human is 33,000 feet, Vesna Vulovic, a flight attendant suck out after an apparent explosion. Terminal velocity is not very high for a fish, especially small fry. It is what makes it relatively easy for them to get airborne to begin with. Landing in water certainly helps also. Some spiders actually specialize in being transported this way, upon exiting the egg sack.

A bigger question than surviving the fall is the likelihood of getting airborne to begin with. I would suspect that waterspouts are only required for cases involving larger fish. The jumping response of some fish to boat motors, which high winds could somewhat mimic, and the feeding behaviors during or following rains do put many species above the surface of the water at inopportune times. For a full fledged waterspout whole schools could be subject to being transported, but high winds are sufficient for smaller fish in smaller numbers if they break the surface at a bad time. Perhaps just trying to escape the monster trying to eat them. This is, in part, why I think it likely that smaller fish in smaller numbers are overall far more likely to get transported unnoticed than these larger fish rain events. All of the fish I seen in our duck pond early that first summer were very tiny sunfish less than an inch. They almost look like baby minnows at that size. Within a few years there were minnows also.

Would the roofs in Australia be likely to trap small fry before reaching the reservoir? And how likely, if a fry actually made it into a reservoir alive, would it be able to survive on the food available in it? I have serious doubts about either of these issues. Even the fiberglass shingles used in the US I doubt a live fry would ever even make it to the gutter, much less to a reservoir. It would be interesting to consider monitoring this or similar situations. Or better yet build a large specially designed entrapment to see what happens over several years.

However, if two valid major fish rain events occur worldwide a year, as I have seen claimed without qualification, then the transport of a few specimens per year in the US is well within reason. Thus it is also reasonable that ever decade or so we will see instances similar to the rosyside dace. Most of which will fail to form a new population. How likely is this really? Nobody has a clue. Certainly far less likely than irresponsible people, but that really says nothing about how likely it is.

If rains of fish were that common, and they spread fish between basins then the whole field of freshwater biogeography and phylogeography would be a waste of time. For the most part we find patterns that are consistent with river basins being isolated from one another and having faunal and genetic differences that are consistent with this. If rains of fish were spreading fish around willy nilly, even once in a thousand years then many biogeographic patterns wouldn't really make any sense.

Would the roofs in Australia be likely to trap small fry before reaching the reservoir? And how likely, if a fry actually made it into a reservoir alive, would it be able to survive on the food available in it? I have serious doubts about either of these issues.

Many houses there have corrugated steel roofs which would be very efficient at transporting anything in the water. I've seen fry survive and grow up in essentially bare tanks with no feeding, thus I'd expect some would be able to survive in a larger water tank.

Cheers
Peter

You have a point, but It would not necessarily invalidate biogeography. The rareness of such events themselves is certainly well below the bait bucket effect, which has not entirely invalidated biogeography as yet. Such events are likely far more common with some species than others. You would not expect benthic zone dwellers, or fish that avoid surface contact, to be nearly as subject to such events. Nor is there any reason to presume that such transport events lack regional or directional variances, like tornado alley in Texas and the prevailing wind directions involved.

In fact I just did some map checking for clues. For instance north central Texas and all of central Oklahoma experiences about nine tornadoes a year per 100,000 square miles. That is a square 100 miles (160 Km) on the side. East of the Texas, Oklahoma, and Kansas borders this falls closer to three, and closer to one east of the Mississippi River. So the weather patterns likely associated with such events have strong geographical characteristics as well as strong prevailing directions of transport. So not only would it not necessarily invalidate biogeography but may even provide some species specific causal factors in historical biogeography if properly studied.

We cannot make presumptions about the total or global likelihood of a phenomena based on observations of one region, or worse yet cherry picked news stories from around the world lacking objective claims. Nor make presumption of randomness about species likely to be involved in such phenomena or the randomness of which geographical regions are likely to have species transported between. Though one off events do occur on occasion.

This is not to say you are wrong, it is merely grounds for at least studying the phenomena to better establish likely characteristics. Certainly defining the phenomena as an ubiquitous random redistribution of species is wrong. That is not to say the phenomena is rare in all cases or lacks relevance to species distribution. The answer is likely to fall somewhere in between the two ends of the spectrum.

Some off topic things personally witnessed associated with storms/tornadoes.
I have seen where small, relatively insignificant, tornado went through a wooded region. You could see where the trees in a thin well defined path were twisted in place splintering the trunk in a circular pattern and laying the trees over in the direction of the tornado path. Often these tornadoes do not even last for 100 yards and fail to be recognized as tornadoes at the time. On several occasions I have seen where straws of hey was embedded in the trunks of trees like nails driven in, a few of which were unbroken. This is a common claim associated with tornadoes, but I can not associate these observations with any particular storm. One time when watching a storm out the widow I seen a large BBQ grill, made from 1/8 inch plate steel too heavy for a grown man to lift alone, lifted a few inches and blew over on its back after traveling several feet. Yet the cheap folding lawn chairs 30 or 40 feet away had not moved, at least yet. The chairs did end up at the tree line behind that duck pond before the storm was over. My uncle had a 2x4 driven through the metal of his truck below the dashboard. It came in between the front windshield and hood without breaking the windshield or damaging the hood. I did at least see the hole though his truck and the broken 2x4 he said did it anyway. The only known actual tornado at the time was about 3 miles away, the same one that twisted the trees. Tornadoes were as common as spring rains where I grew up, but often smaller and shorter lived than the ones common just a few miles to the west, where my brother in laws mother was killed in one.

I found an inactive research project, Tornado Debris Project.
http://www.gcn.ou.ed...ebris/BAMS.html

Several times each year tornadoes strike communities in the United States, damaging homes, businesses, and other structures. Great efforts have been made to understand how tornadic winds damage structures. Less attention has been given to other, closely related phenomena. While there have been a few efforts to investigate low altitude lofting and deposition of material by tornadic windfields (usually motivated by an interest in missile hazards), the lofting of debris to great heights, its long-distance transport, and its fallout far downstream from its source have received little attention. Indeed, most of our knowledge of such phenomena is anecdotal -- the newspaper clipping reproduced in Figure 1 is typical. These phenomena pose interesting scientific questions and challenges, and are the subject of this paper.
[...]
While showing conclusively that lofting, debris transport, and fallout occur, Anderson's study is the only one of its type in modern times (see Peterson, 1993, for discussion of three early European studies; these are mentioned briefly below). It does not provide a sufficient basis from which to judge either how often these phenomena occur or what happens in tornadoes of lesser intensity.

Take a look at the graph showing the debris field as a function of the debris weight, where "heavy" is designated as objects over one pound.

Source: http://www.gcn.ou.ed...Spreprint1.html

Note that even the heavy objects are routinely transported out to 45 to 50 miles with cases shown in this dataset going out to 110 to 115 miles (sample size 163). Few fish would meet the requirements for a "heavy" object. Transport of this type would primary be limited to a northeasterly direction in the eastern US, especially over any significant distance.

This shows that any fish which becomes part of the debris most certainly can be transported to highly significant distances. Presumably most such fish are closer to an ounce or less rather than anything approaching a pound. Even the data on the general (obvious) debris field created by such storms is extremely limited, much less on biological transport. More data is needed for a wide variety of reasons, including ecology. How likely, given a storm system over water capable of producing a debris field, is it that a fish would exit the water to become part of this debris field? Obviously if the rotation extended into the water column the odds would be greatly increased. They will likely jump, much like fish caught in a net. The same could be expected if spooked by a sudden change in water pressure. The tornado overhead could easily be mistaken for an approaching predator. Some fish also becomes quiet active in a thunderstorm and seen hitting the surface a lot, apparently feeding on insects knocked down by the rain.

Tornado Strangeness:
Here is an of examples of tornado strangeness. In this video it throws two cars in opposite directions while a lot of cars around them remain unmoved. If you look close that was the result of a very tiny tornado, really not much more than a large dust devil.
http://www.youtube.com/watch?v=peFOyiYVWm0

I read that Texas Tech University managed to reproduce the straw embedded in trees effect. Apparently the vortices's will twist or bend the tree opening up cracks in the wood fibers. Straw then gets embedded in these cracks which then close back up when the wind passes.

You have a point, but It would not necessarily invalidate biogeography. The rareness of such events themselves is certainly well below the bait bucket effect, which has not entirely invalidated biogeography as yet.

Bait bucket / fish translocation has only really been around for 150 years and it has totally screwed up the biogeography of the worlds fishes. Many western USA states barely resemble their native pre European faunas as most states have 1-3 times more non natives than natives, and in many cases the exotic fish out number and out range what's left of the natives. Many eastern states have suffered greatly too. New species keep showing up in rivers where they were previously absent every year. I know this goes on in Oklahoma as well as North Carolina and Virginia. I'm sure it is the same in most states these days. Look at Florida. And of course it is easy to tell when species previously absent have been translocated, but it is very difficult to identify translocations of species on top of the same species in a new drainage and these events are probably pretty common too.

Dispersal combined with time is a very powerful force in biogeography, look at how islands get colonized. Again, there has been more than enough time for rains of fish to move stuff around (if it were a common event) and it would show up in biogeographic patterns (not all, but at least some). I also think that most rains of fish are probably very local events and that the fish are rarely if ever moved between river catchments.

This is not to say you are wrong, it is merely grounds for at least studying the phenomena to better establish likely characteristics. Certainly defining the phenomena as an ubiquitous random redistribution of species is wrong. That is not to say the phenomena is rare in all cases or lacks relevance to species distribution. The answer is likely to fall somewhere in between the two ends of the spectrum.

I'm all for folks trying to study it, one of the problems is that it is not easy to study it (ethics approval for putting fish in wind tunnels / emulating tornado conditions might be a little tricky since I think the well being of the critters would be difficult to justify). And you are correct, not all species would be equally likely to get transported / survive. But even most widespread ubiquitous species usually show phylogeographic patterns where different basins tend to have different stocks present and these are probably the most likely species to be picked up by a storm (since they are often quite abundant/widespread) and they are often the most difficult species to kill.

Neat stuff in your other post on how far stuff gets carted by tornados. But the longer I think a fish is carried the less likely it is to survive. It starts to get cold pretty quickly as you go up in altitude.

Cheers
Peter

This is interesting, and you are correct that my speculations lack any solid empirical grounds and depends more on a lack of data to justify. Thus good skeptical rebuttals as you have provided are of particularly high value. This issue of bio-distribution and invasion is particularly problematic. Certainly the limiting factors must be significant. The rosyside dace this thread is based on is particularly problematic.

A large variety of factors would influence the potential for storm transport, aside from the regional and directional storm characteristics. An attempt to list these would include:
1) Species habits lending to the potential for getting caught in storm debris.
2) Initial population sizes, larger species population are more likely to have some individuals caught in storm debris.
3) The need for enough members of a species to establish a breeding colony in a contingent environment.
4) The life spans of species that increase/decrease the probability of transport of breeding pairs in contingent environment.
5) Species capacity to survive the transport in storm debris.
6) Species capacity to survive the environments the debris might fall in.
7) The propensity for subspecies previously transported and subsequently diverged to reabsorb newly transported specimens.

Unlike bait bucket and intentional introductions, these storm transports would be of very low intensity. This allows local populations to usually deal with, reabsorb, or out compete these storm introductions even in cases where breeding populations were potentially possible. Something that cannot be done when bait bucket or intentional introductions involve high numbers of instantly available breeding populations. So to make any case on the available data looking at a few individual species cases would be useful. Any other species cases fitting this profile for likely storm transport would be appreciated, especially clear cases of exceptions.

The two I will consider here is the green sunfish (Lepomis cyanellus), which first showed up in our duck pond, and the Alligator Gar (Atractosteus spatula). The green sunfish for obvious reasons of personal observations and the Alligator Gar due to high survivability in a range of conditions, including breathing air, high lifespan, 60 to 70 years giving the potential for waiting dozens of years for a breeding partner, and low geographic distribution contrary to expectations of an indiscriminate distribution mechanism.

Lepomis cyanellus:
For the green sunfish consider the following source:
http://maps.gis.iast...s/IA168132.html
These fish are essentially ubiquitous throughout the US. What is said of the the state of Iowa here essentially applies everywhere.

The green sunfish is undoubtedly one of the most widely distributed fish in Iowa and is the most wide-ranging sunfish species (Harlan et al. 1987). It is found in every watershed in the state. This ubiquitous fish is found in streams of all sizes but reaches its greatest abundance in natural lakes, man-made lakes and farm ponds (Harlan et al. 1987). The green sunfish inhabits the full length of the Mississippi River, and is prevalent in the prime habitat created by the riprap armoring placed along the banks of the Missouri River (Harlan et al. 1987).

Even more interesting is the "Habitat Affinities".

The green sunfish can be found in a wide variety of habitats ranging from small muddy creeks and weedy backwaters with temporary flow to overflow ponds, shallow lakes, impoundments and occasionally, the margins of large rivers of low gradient (Becker 1983; Cross and Collins 1995; Eddy and Underhill 1974; Phillips et. al. 1982; Trautman 1981). The green sunfish is commonly found near shore and around cover such as stems of vegetation, woody debris, or rocks (Cross and Collins 1995), and has no specific substrate preference (Robison and Buchanan 1988; Trautman 1981). Its high tolerance for extremes in turbidity, siltation, low oxygen, temperature and flow allow it to inhabit, and reach greatest abundance, in areas that do not support other sunfishes (Clay 1975; Pflieger 1997; Robison and Buchanan 1988). In the Central Plains Aquatic Subregion, the green sunfish is well adapted for survival in small streams with intermittent flow that become stagnant pools later in the summer and fall. A pioneering species, it is often the first fish to find it way to newly created farm ponds (Smith 1979) and first to repopulate Plains streams after droughts (Pflieger 1997; Tomelleri and Eberle 1990).

They apparently specialize in surviving adverse conditions and being the first to populate new environments. For the life of me, even if this species survived dry periods in the creak flood regions to the west and came within the vicinity of the duck pond, I cannot imagine how they would cross the embankment into the duck pond. It was several years before the pond, after some heavy rains, filled sufficiently to produce an overflow channel. Even then the drain channel was initiated by rain directly impacting the embankment, lowering it, to eventually have a channel low enough to produce an overflow. It remained a large puddle in the bottom of a hole for a long time.

So here we have a species with huge numbers over a huge geographic, greatly increasing the likelihood of becoming part of storm debris, while specializing in surviving the very conditions needed to survive storm transport. Not many species would have the numbers, range, survivability, surface interaction, etc., to mimic these numbers over even a reasonable slice of geologic time. If breeding colonies fail over the short term then no amount of geologic time will effectively provide breeding colonies.

Atractosteus spatula:
This species has a very long lifespan with a high survivability in highly adverse environmental conditions. Though larger specimens are presumably far less likely to be storm transported this species can effectively wait dozens of years for an effective breeding partner. So the question is why would there historic range be so limited, and can storm transport play any role in the historic range they did have?

The following range map was taken from:
http://wildedtx.blog...rve-better.html

Keys:
Green - Naturally Sustaining Populations
Orange - Remnant Populations or Individual Observations
Red - Stocked Population
Yellow - Approximate Historic Range (Possible Extirpated)

Here it is obvious that throughout the range 'swimming there' could easily be the primary mechanism of transport. But why is the the historic distribution to the northeast so extensive while failing to 'swim to' far closer available habitats in any other direction? In fact many easily available habitats far more similar than the northeastern extent are orders of magnitude closer and easier to 'swim to' which they did not even successfully cross the state in the northwesterly direction. Meanwhile they historically crossed many more mile to the northeast. The Mississippi River plays a significant role here but look at another map:
http://www.sdafs.org.../AGar_Maps.html

Note how the northwesterly splits in Arkansas and Missouri are significantly limited in spite of plenty of river access to continue, while the northeasterly track continues unabated. Notice also that these northwesterly splits remain in a northeasterly line with preexisting populations to the southwest. So mere river transport and access (swimming there) does not fully account for this progression of historic range. In fact it more closely follows historic storm transport routes. Otherwise there is no real explanation of why they would fail to progress up one leg of a river while progressing up the other northeasterly leg unabated. This historic distribution matches almost precisely how the winds off the Gulf move inland and are caught by easterly winds from the rockies and bent in an easterly direction. It is this confluence of warm Gulf moisture, easterly winds, and northern cold fronts that produce these historic storm tracks. Over geologic time this historic storm track likely also help produce the general drainage patterns seen today. Also, it is fairly obvious that the ancient populations originated in coastal regions, all the way down the eastern coast of central America.

At least in principle it appears to follow the hypothesis. Any counterexamples to these cases? Coastal regions east of Louisiana are far more limited in storm penetration from the Gulf, except where it crosses over Florida. The Smoky Mountains form a natural push line diverting weather systems in an arc over the region. Hence the Etowah River drainage system in Georgia is effectively isolated from these storm transports with a resulting isolation and subsequent high degree of biodiversity relative to other regions. Another reason why the Etowah Watershed is imperiled by exotic incursions introduced by people. So this storm transport model also correctly predicts biologically isolated regions.

This model is little more than suppositions which may be misleading. Yet on the data we have it cannot be empirically rejected. Even if misleading it still remains to be explained why its general characteristics apparently have some level of explanatory power.

I truly do appreciate your capable rebuttals. Any (counter)-examples?

I was comparing the distributions and life history of Longnose and Shortnose gar. The Shortnose gars range goes more directly north and somewhat west at the northern end of the range. Though its range almost avoids Texas altogether, except around the borders. It makes it appear like a subspecies that evolved in the north and spread south along the drainages. It also has a much shorter life span and maturity rate. 3 and 17 to 20 years.

The Longnose gar has the most extensive range, including Florida, Georgia, north to Canada and west to South Dakota. This gar also has a fast maturity rate and similar life expectancy to the Shortnose. Moving inland from coastal regions farther east than the Alligator gar, such as Florida, would give a greater range through Georgia by standard range expansion methods. The young have an intriguing characteristic. The fry will attach themselves to debris in shallow water while their sac is being absorbed. Such debris would actually provide some level of protection during storm transport and, if the debris is storm transported in whole, could provide a ready means of establishing a breeding colony in a single storm transport event.

I do not know much about the genetic history or phylogenic history of gar. I would suspect, based on the maps, that the Alligator gar is closest to the oldest lineage, while the Shortnose gar was a relatively newer subspecies the evolved farther north. I am not sure where to place the Longnose gar, but appears to have evolved to deal with more temporary floodplains while still having a strong coastal presents. Even in the Rio Grand and further east than the Alligator gar into Florida. So I suspect it predates the Shortnose gar. So I suspect the Shortnose is actually a subspecies of the Longnose gar, which earlier split from the Alligator gar or common ancestor.

These are wild guesses I hope to compare against actual data if and when it becomes available. Anybody have any information on the evolutionary history of gar?

As for fish colonizing the pond surrounded by an embankment, alot of people have told me that waterfowl can carry fish eggs on their legs. Not sure how true it is. I do however know sunfish and bullhead have a habit of appearing in new ponds mysteriously.

Then again sunfish and bullheads are commonly moved and stocked by anglers too, especially kids who bring fish home do not want to clean them, and dump them in nearbye waters. (when I was a stupid little kid and clueless of the consequences I was guilty of this and stocked a few small fire ponds).

They apparently specialize in surviving adverse conditions and being the first to populate new environments.

Right, they are an extremely good colonizer. So why is there any need to invoke rains of fish to explain something that already has a solid biological basis? Could they be spread by rains of fish, sure, but clearly they have exceptional drive to find new places to live and need no help to colonize new habitats. This drive is easy to understand too, they will live in very crowded conditions and they are fairly nasty to each other. When given a chance they want to find a better life. It's exactly the same story with the fish most commonly said to occur in rains of fish in Australia (spangled perch, Leiopotherapon unicolor). They are the most widespread fish in Australia and they clearly have an intense drive to disperse. They tend to overcrowd and they are nasty to each other. They have been observed swimming several miles over a couple of hours along a wheel rut in outback Western Australia after rainfall. At times their backs were out of the water as it was only probably 2 inches deep.

You might not be able to imagine how they swum into your new farm pond, but clearly they are not only capable, but one of the best species at achieving it! Is it possible they didn't swim there, sure, but the fact that such an event is commonly observed (that sunfish colonize quickly), the most likely explanation is they swum there.

There are always multiple potential explanations for just about everything (and it is good to keep these in mind), but you seem to wish to focus on the less likely ones. As I said earlier, quoting Carl Sagan (I think), extraordinary claims require extraordinary evidence. The evidence for rains of fishes is pretty limited. In your case better evidence would be the presence of fish species that are not good colonizers (although such information is not well known, but can be inferred from how widespread/common a species is). But one could also start invoking things like eggs on birds which is another extremely unlikely way for fish to get moved around, but not completely impossible either.

Cheers
Peter

These are wild guesses I hope to compare against actual data if and when it becomes available. Anybody have any information on the evolutionary history of gar?

Don't forget to include the ecology of the organism. It's not just a simple matter of swimming (or flying) upstream.

Todd

As for fish colonizing the pond surrounded by an embankment, alot of people have told me that waterfowl can carry fish eggs on their legs. Not sure how true it is. I do however know sunfish and bullhead have a habit of appearing in new ponds mysteriously.

Then again sunfish and bullheads are commonly moved and stocked by anglers too, especially kids who bring fish home do not want to clean them, and dump them in nearbye waters. (when I was a stupid little kid and clueless of the consequences I was guilty of this and stocked a few small fire ponds).

I have heard the waterfowl explanation also. It cannot be ruled out entirely and the possibility remains that the storm transport mechanism might be off base. Yet nobody really knows. As the previous studies mentioned show we know frightfully little about even the obvious components of storm debris fields, much less particular content types in this debris such as fish. What I would like to see is a number of specially built catchments, especially within these storm track regions of the country.

In latter years the possibility of stocking from a lot of us kids is likely a near certainty, from fishing the pond across the road and other sources. Though I personally did not or know of a particular case of such stocking. Also, when later we got a bulldozer to dig a much bigger pond I have much less cause to question storm transport for stocking, even though it remained a reasonable assumption. I do remember being disappointed the bulldozer so thoroughly wiped the original duck pond clean when it got started. It was the first month or two following the hand digging of the original small duck pond in our back yard that is the hardest to fathom without some undocumented transport mechanism. I spent nearly all my free time around this pond and the woods behind it. My first aquarium fish was from this duck pond, caught using window screens as nets.

Don't forget to include the ecology of the organism. It's not just a simple matter of swimming (or flying) upstream.

Todd

Yes, I made a quick list for comparative ecology, but a lot of detail is lacking. These gar in general tend to use shallow reedy flood regions for reproduction. They also tend to be associated with oxbow lakes, so they have been around since long before the watershed characteristics we now know existed as such. There are obviously a lot ways for gar to established themselves in known habitats without resorting to undocumented mechanisms. The question I was asking was one of consistency with rather than specific methodology of transport.

I did notice that throughout their range gar tend to be mostly absent in the extremities of the watersheds they inhabit, in spite of the apparent ease of access. Gar do not tend to migrate much either. They appear to have a preference for larger deeper water systems. For the Alligator gar the easterly extent of the historical range is mildly odd considering to availability of equally large and accessible rivers to the northeast with a generally equivalent range of ecologies. Inconclusive with respect to evidence for anything. It certainly makes no sense to presume some hypothetical low intensity transport mechanism is going to explain over are large number of well established standard transport mechanisms.

Right, they are an extremely good colonizer. So why is there any need to invoke rains of fish to explain something that already has a solid biological basis? Could they be spread by rains of fish, sure, but clearly they have exceptional drive to find new places to live and need no help to colonize new habitats. This drive is easy to understand too, they will live in very crowded conditions and they are fairly nasty to each other. When given a chance they want to find a better life. It's exactly the same story with the fish most commonly said to occur in rains of fish in Australia (spangled perch, Leiopotherapon unicolor). They are the most widespread fish in Australia and they clearly have an intense drive to disperse. They tend to overcrowd and they are nasty to each other. They have been observed swimming several miles over a couple of hours along a wheel rut in outback Western Australia after rainfall. At times their backs were out of the water as it was only probably 2 inches deep.

Yes, I have observed fish trapped in wheel ruts in pastures in Texas. I could even trace the wash region to a source and it often involved much less than 2 inches of water. The fish will even swim on their sides against the ground to escape. though it was without exception always downhill from the source no matter how slight that downhill gradient. Yet the regions that could in any sense be consider a drainage to any source for our duck pond included miles of woods in which even the heaviest rain would not even disturb the leaf litter on the forest floor. Not only was there several miles of this but the gradients needed to be climbed was extensive. These fish also tend to in the direction of the water flow from any source overflows, something the fish would have had to go against for several miles up extensive gradients, in total at least 15 or 20 feet uphill, to even get in the region of the pond. Then there is a numbers problem ever bit as big as conceived for storm transport numbers. Even if these fish migrated over sufficient distance to reach the pond, the numbers of fish required to do this for one to find the pond in any reasonable period of time would require observing fish on the forest floor to be common. This would not apply for eggs or small fry with a diffuse random distribution over a storm track.

You might not be able to imagine how they swum into your new farm pond, but clearly they are not only capable, but one of the best species at achieving it! Is it possible they didn't swim there, sure, but the fact that such an event is commonly observed (that sunfish colonize quickly), the most likely explanation is they swum there.

When you say commonly observed it is misleading. What is actually observed is after the fact colonization from which it is often fairly easy to conceive how they swam there. A pond below the overflow of another pond or lake is no mystery, regardless of how well netted that overflow is thought to be. I would be willing to bet the spangled perch traveling the tire track was at least traveling in a general downhill direction, even if only slightly so.

There are always multiple potential explanations for just about everything (and it is good to keep these in mind), but you seem to wish to focus on the less likely ones. As I said earlier, quoting Carl Sagan (I think), extraordinary claims require extraordinary evidence. The evidence for rains of fishes is pretty limited. In your case better evidence would be the presence of fish species that are not good colonizers (although such information is not well known, but can be inferred from how widespread/common a species is). But one could also start invoking things like eggs on birds which is another extremely unlikely way for fish to get moved around, but not completely impossible either.

Cheers
Peter

Yes, my argument is explicitly geared toward storm transport of fish, which I could certainly be wrong for all practical purposes. I focus on this one mechanism simply because of the potential ecological relevance which we otherwise have no real data on. So the fact that I geared the argument around storm transport is simply a matter of expediency in making the case, and in no way represents any rejection of more likely mechanisms. More standard mechanisms are almost certainly many orders of magnitude more common, but still fails to recognize the potential importance of such a mechanism by simply ignoring the need for any data on the matter.

I think this is a worthy issue to study. Ideally a series of raised platform pools in high storm regions could be used to place limits on such a mechanism. Bird transport would also need to be controlled for, and in some cases specifically tested itself. Bird transport could be as ecologically significant as any storm transport hypothesis. Regardless, negative data is far superior to no data and my personally observations do not represent any kind of actual data supporting anything. So as far as extraordinary "claims" is concerned there is no such "claim". Merely a hypothesis needing real data to rule out, and can no more be ruled out by a lack of data than my personal observation can be construed as real data. The "extraordinary claims" is simply not applicable, only actual data is, which is lacking. Neither should the lack of data be used as justification to claim the lack of need for data to access the falsifiability of a hypothesis. The hypothesis certainly requires no goofy compound claims like the ghost shows on science channels, as such a hypothesis contains natural mechanisms with well defined conditions of falsifiability.

So far as I know no species of catfish ever colonized our duck pond. Though the pond across the road had a lot of catfish of unspecified species. I never seen any in the small creeks in the area either, which I constantly waded. Though they certainly had access as my dad latched onto a 40 pounder in Lilly creek, which was far bigger than most local ponds but had a year round creek feeding in and out of it.

They appear to have a preference for larger deeper water systems. For the Alligator gar the easterly extent of the historical range is mildly odd considering to availability of equally large and accessible rivers to the northeast with a generally equivalent range of ecologies.

I would hardly call the difference from glacially recharged, high gradient, cool-water central forest streams AND alluvial plain, low gradient, warm water cypress / cane break big rivers EQUIVALENT!

The Ohio, for example was two completely different rivers above and below the Falls of the Ohio. There may have been patches of low gradient segments above (or gravel and cobble riffles below this point), which would allow the alligator gar to be present above the Falls... However in light of anthropogenic disturbance, these patch populations were easily extirpated.

You're going to have to look at much much more than "the scale of a connecting channel" to examine the environments that select on the genes... If it were just a simple line, why evolve into something else? That would be almost as random as your Red Bull fish hypotheses

Todd