25 replies to this topic

[centrarchid]

Yesterday we setup to create hybrids between Orangespotted and Green Sunfishes with crosses being made each way.  They will be compared to pure Orangespotted and Green Sunfishes grown under similar conditions.  Conditions involve 0.25 acre ponds with cages containing adults and nest.  Adult will be removed after 3 weeks to limit number of cohorts produced.  Fish we acquired from hatcheries (state and commercial) were in exceptional condition.  I bet first spawns will be realized within 24 hours.  

 

Orangespotted Sunfish even in bags act differently from any sunfishes I have worked with.  Males where attempting to setup nests in shipping bag.  I have bred these critters before but never under more natural social conditions where those colors and displays actually come into play.  

 

 

Extra fish (8 males and 2 females) were setup in a 75-gallon tank to observe breeding behavior.  Observations will be on those.  Females are good and ripe.

[centrarchid]

Images to date.

 

Orangespotted Sunfish (male above and female below).

 

 

 

Nesting setup in 75-gallon aquarium.

 

Three males and one female.  Notice all oriented towards me.  Other sunfishes I work with do not react the same unless interested in me as a food source.

 

 

 

Green Sunfish (male above with white trim on anal and pelvic fins.  Males, especially when larger, have a smokey area around vent.

 

[NotCousteau]

Interesting! Thanks for sharing.

[mattknepley]

That "face to the camera" orientation is pretty interesting. Is it something you've seen with other o-spots, or just this crew? Have never seen a live O-spot, but like you, I can't say I have ever noticed it to be a trend in other sunfishes.

[centrarchid]

It appears all lots stocked into ponds have produced broods.  Those in tank above have not done so.  Temperature needs to be elevated.

 

Orangespotted Sunfish in cages also more inclined to look at you head on while Green Sunfish do the lateral thing and slip away.

[centrarchid]

it took too long to get spawn off in tank.  Eggs are smaller than those of bluegill, close to the size of crappie and Bantam Sunfish.  Eggs noted at 1000 but not present at at 1000 yesterday.  Lots of movement of embryo, including heart.  I bet hatch will be underway by end of work day.  if that is correct then hatch time will be less than 36 h post-fertilization.  These little dudes will be tough to rear using our standard larviculture methods where we normally start off with freshly hatched BS nauplii.

 

 

 

Captured image not as good as I see under scope.

[centrarchid]

Prolarvae were emerging from eggs by 1600 yesterday.  This means fertilization to hatch interval of Orange-spotted Sunfish is no more than 30 hours when incubation temperature is 25 to 26 Celsius.  This is the shortest I have observed for any Lepomis sp.  Typical nesting habitat of this species may require such rapid development.  Now will will track time to transition to larval stage / exodus.

[centrarchid]

Picture of prolarval Orange-Spotted Sunfish. Movie also made although having trouble uploading.

 

You can just barely make out 2 otoliths.

[dredcon]

Good stuff. I always love seeing larval stuff.

[centrarchid]

Good stuff. I always love seeing larval stuff.

You have not seen any larvae yet.

[dredcon]

You have not seen any larvae yet.

Prolarvae are close enough for me, although they are more of a pain to pick out of a big larval sample size the eyes don't pop yet.

[Michael Wolfe]

Movie also made although having trouble uploading.
 

Movies don't upload directly to the forum. You have to put them on Vimeo or YouTube first and then link them here and they will show up as playable.

[Betta132]

Cool! They don't even look like fish at that stage.

[centrarchid]

Some of the prolarvae are neutrally buoyant and orient themselves like free-swimming larvae.  Pectoral fins move like a hummingbirds wings.  I think the entire early life-stage progression is designed to get them out of the nest fast.  

 

 

 

 

Sires on nest typical in their brood care methods.

[centrarchid]

Yolk almost absorbed.  Exodus will occur tonight.  This means larvae on their own 5 days post-fertilization.  Bluegill require no less than 6 days and can go 11 days when temperatures are low.  Orange-spotted sunfish are all about short turn around time.

[gzeiger]

How small are the eggs? Powdered high-protein flake foods work well for some of the smaller cichlid fry.

[centrarchid]

Egg diameter not measured directly this round.  I will have a measurement of gape size.  Larvae of Lepomis spp. may not be a good at handling prepared foods as cichlids.  Smallest cichlid larvae I have experience with (Ram Cichlids) are a lot bigger than these guys.  The Orange-spotted larvae are not much bigger than those of Paradise Gouramies.  This appears to make them smaller than even crappie.

[Betta132]

Could their quick development be due to the inability of the comparatively small parents to protect them from significant threats? Maybe the goal is to get them able to avoid predators as quickly as possible, since their parents are too small to fend off most threats.

[centrarchid]

I think for some reason the males do select nest sites that are shallower and more exposed than other sunfishes.  Shorter time there would be good as you suggest.  Additionally in locations I have seen natural nests, the locations are much more vulnerable to variations in water level.  Species that come closest to using shallow water nesting sites are Green Sunfish and Warmouth.

[Evan P]

I regularly seen them nesting on or near boat ramps. They seem to take advantage of spots often ignored due to the variability, as others have mentioned, and the quick fry growth makes sense. Very cool.