
Big For Fundulus Dispar
#2
Guest_Brooklamprey_*
Posted 02 September 2007 - 09:04 AM
I have some Fundulus dispar from SW Michigan.
Is the maximum size for these fish different from F. dispar found in other parts of the country?
Related topic: Regional Differences in Fundulus, Is there a difference?
I have never noticed a size difference from those found in Indiana or elsewhere. If you do not mind me asking where where yours collected??
#4
Guest_Brooklamprey_*
Posted 02 September 2007 - 08:40 PM
I suppose you have 3 inch long F. dispar in your aquariums. That is how big Peterson's say F. dispar get.
I have only seen 2 inch F. dispar in Carter Lake, Hastings, MI.
I have sampled 1.5 to just under 2 inch fish From Indiana and Barrien, Branch and hillsdale counties in Michigan and have sampled and kept some from Arkansas and Wisconsin some years back. None where 3 inches ever...
I have never seen a three inch one...In captivity or in the wild.
In captivity, My Branch county group has never really reached beyond 1.5 to 2 inches in captivity and the Indiana the same. A friend and Coworker that keeps a Minimal sized population of the Indiana population that I gave her has shown me one male that was a touch over 2 inches at about 2 1/2 but I take this to be environmental and she really likes to supplementary feed them..
In practice I have not seen a large disparity in size, coloration, or general disposition in any of these various populations.
#7
Guest_dsmith73_*
Posted 04 September 2007 - 10:18 AM
my big male is a good 3.5 inches hes so big I now feed him a diet of mostly feeder fish
This is a little hard for me to swallow. I find it very hard to believe that you are feeding a topminnow feeders. Are they newborns? I have seen some huge killies in the past, such as some 6 inch studfish and some 5 or so inch olivaceous and even these fish do not have the mouths for feeders.
#9
Guest_wegl2001_*
Posted 04 September 2007 - 01:01 PM
Dustin,This is a little hard for me to swallow. I find it very hard to believe that you are feeding a topminnow feeders. Are they newborns? I have seen some huge killies in the past, such as some 6 inch studfish and some 5 or so inch olivaceous and even these fish do not have the mouths for feeders.
I had a tank filled with java moss that housed E. evergladei and F. notti. They co-existed for months with the pygmies actually spawning and raising fry. The notti stayed at the surface and seemed to be unaware of the pygmies. Then one day, while doing a water change, I accidentally drained the tank to within 3"-4" of the bottom. Two of my largest male notti's were swimming around with pygmy tails (no comment Irate) hanging out of their mouths. They eventually swallowed them. After I raised the water level things went back to normal.
#10
Guest_killier_*
Posted 04 September 2007 - 01:22 PM
smaal feeder guppies but I feed alot of things feeder fish that pic of the 4 inch female mummichog I sent you when it died ate my 3 inch banded killi a few weeks before it diedThis is a little hard for me to swallow. I find it very hard to believe that you are feeding a topminnow feeders. Are they newborns? I have seen some huge killies in the past, such as some 6 inch studfish and some 5 or so inch olivaceous and even these fish do not have the mouths for feeders.
#11
Guest_teleost_*
Posted 04 September 2007 - 01:23 PM
my big male is a good 3.5 inches hes so big I now feed him a diet of mostly feeder fish
I'm also suspicious of a 3.5" dispar as well as feeding them pet shop feeders. I've seen lots of dispar in both northern and southern Illinois and not once have I seen one that size. Are you talking about F. dispar Killier?
I can also say that I had them actively hunt gambusia young while ignoring medium size gambusia they could easily fit within their mouths. It seems a switch would turn on once a female gambusia gave birth. The young never seemed to last more than a few days and I never really had a population replacement due to predation. I'm not sure if the fish were hungry or this was simply self preservation

#13
Guest_Brooklamprey_*
Posted 04 September 2007 - 02:21 PM
MI, WI, northern IL, or northern IN
Thanks for all the responses.
Please let me change my question:
What is the biggest Fundulus dispar caught in MI, WI, northern IL, or northern IN?
In my personal experience sampling for them in Indiana, Michigan and Wisconsin, size was not much over 2 inches and often smaller. This could be biased for smaller fish as most where caught later in the year in late summer or fall and I have not sampled much for them earlier in the year.
#14
Guest_killier_*
Posted 04 September 2007 - 02:32 PM
it ate larger ones when I first got it so it was hungry but it has always hunted down feeder guppies(less than 3/4 on an inch) andgts 1-2 every time I feed my sunnies and my mummichogs eat almost a dozen every weekI'm also suspicious of a 3.5" dispar as well as feeding them pet shop feeders. I've seen lots of dispar in both northern and southern Illinois and not once have I seen one that size. Are you talking about F. dispar Killier?
I can also say that I had them actively hunt gambusia young while ignoring medium size gambusia they could easily fit within their mouths. It seems a switch would turn on once a female gambusia gave birth. The young never seemed to last more than a few days and I never really had a population replacement due to predation. I'm not sure if the fish were hungry or this was simply self preservation
who knows I bet if someone had a large mummichog or starhead and put in some feeders I'm sure they would chow down
#16
Guest_uniseine_*
Posted 04 September 2007 - 04:48 PM
"A length-frequency plot of 316 Fundulus dispar collected at the SIUC [Southern Illinois University at Carbondale] pond on 11 March 1993 was strongly bimodal, suggesting 2-yr classes [ILLUSTRATION FOR FIGURE 4 OMITTED]. No sexual dimorphism in size was noted. Standard lengths of individuals ranged from 15-38 mm." from article below
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Reproductive biology of the northern starhead topminnow, Fundulus dispar (Osteichthyes: Fundulidae), with a review of data
for freshwater members of the genus.
Publication: The American Midland Naturalist
Publication Date: 01/01/1997
Author: Taylor, Christopher A. ; Burr, Brooks M.
Spawning bouts (n = 4) were observed on three separate dates: 29 April, 1 May, 22 May 1991.
the largest number collected on a single day was 15 (from 6 females) [Does not sound impressive. I have one female Fundulus rathbuni lay 14 eggs, 2.5 mm diameter eggs found in one mop, in one day.]
Spawned eggs averaged 1.9 mm in diam (range 1.81-2.07 mm, n = 50; SD = 0.06).
in the spawning cage, when presented the choice of a flat rock and mops attached to the top and bottom of the cage, 74% of
spawned eggs were found in mops resting on the bottom.
#18
Guest_Brooklamprey_*
Posted 04 September 2007 - 05:36 PM
38 mm as the biggest SL? That's only about 1.5 inches!
1.5 inches really seems like a rather average size from my sampling. Larger fish than this are really few and far between.
Attached are Excel files from UMMZ collection fishes..There are no Wisconsin fish in the collection so this covers Michigan, Illinois and Indiana. Largest is just 53mm for Michigan.



#19
Guest_fundulus_*
Posted 04 September 2007 - 07:03 PM
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