Learned something today about blue gills

[Rays of Sunshine]

I went to the lake., looking for driftwood and and my favorite...algae. I had taken some fish food with me and threw a few flakes to the 1/2 inch or less babies at the edge.

I watched about 20 young blue gills swimming by. I spotted the largest one and thought, I might catch this one. I gave the babies the last of the food and a few babies started moving away from the edge chasing food.

I hadn't noticed that the blue gills had stopped and were watching the babies. I saw a 1 inch blue gill try to eat one of the babies out too far. I looked and saw all of the blue gills right behind it in formation like soldiers.

A few charged the babies out too far and grabbed a few. I had never thought of the smaller blue gills stalking the babies on the edges. I had only seen the bass do it.

I thought dang it is hard to be a baby fish. Everything is out to eat you and I just rang the dinner bell for your predators by giving you fish food.

 

[fatherof5]

I thought you knew big fish eat little fish LOL,

 

[Northern Pike]

I thought you knew big fish eat little fish LOL,

 

[JIM]

Predation in nature is pretty much rampant, and thats a good thing as most all native fish produce rather large familys.

If it wasnt for the predators, most lakes and rivers would be stuffed so full or fish they couldnt swim, and the food sources would disappear pretty quickly

 

[Madding]

I don't know about bluegills, but I've read that less than 5% of fish hatchlings actually make it through the first year. I can't remember the species, but I am assuming that predation means that almost 95% of most fish are killed shortly after being born. Waterways would be extremely overstocked otherwise. The enormous number of eggs is also natures way of knowing that it's going to take a lot for just one of those little fish to make it to adulthood.

 

[Rays of Sunshine]

I know blue gills eat other fish, however I have never seen the group attack formation or the bass like behavior of so many and so young.

 

[warmouth]

Rays of Sunshine, Bluegills usually dont eat their own fry (unless theyre in a closed enviroment and very hungry) they will eat another fishes fry (even another Bluegills) heres a summary of a study I found using Google.
Bryan D. Neff1 and Paul W. Sherman2
(1) Department of Biology, University of Western Ontario, ON N6A 5B7, London, Canada, (2) Department of Neurobiology and Behavior, Cornell University, NY 14850, Ithaca, USA,
Received: 12 October 2002 Revised: 22 January 2003 Accepted: 17 February 2003
Parental care can be costly to a parent in terms of both time and energy invested in the young. In species with cuckoldry or brood parasitism not all of the young under a parent's care are necessarily offspring. In such cases, distinguishing between kin and non-kin, and investing only in the former (nepotism), can be advantageous. Bluegill sunfish (Lepomis macrochirus) are characterized by paternal care and cuckoldry, and care-providing males appear to show nepotistic behaviours. Here, we investigated nestling recognition in bluegill, determining whether parental males can differentiate between young from their own nest (familiar and related) and young from non-neighbouring nests (unfamiliar and unrelated) using (1) visual and chemical cues, and (2) chemical cues only. In the first experiment, wild-caught parental males were presented with samples of eggs or fry (newly hatched eggs) collected from their own nest or a foreign nest and placed on opposite sides of an aquarium. The time these parental males spent associating with each sample, and their "pecking" behaviours (indicating cannibalism), were recorded. Parental males showed no preference between eggs from their own nest and eggs from a non-neighbouring nest, but they preferred to associate with fry from their own nest over foreign fry. There also was a positive relationship between male body size and the time spent associated with fry from their own nest. Parental males pecked at foreign fry more than 5 times as often as fry from their own nest, though this difference was not statistically significant. In the second experiment, fry that were collected from the nest of a wild-caught parental male or a non-neighbouring nest were placed in different containers and the water from each was dripped into opposite ends of an aquarium. The time the male spent on each side was recorded. In this case, parental males spent more time near the source of water conditioned by unrelated fry, but there was a positive relationship between male condition (fat reserves) and the time he spent near the source of water conditioned by fry from his own nest. Results confirm that chemicals cue nestling recognition by parental male bluegill.


Kin recognition Olfaction Paternity Parental care Bluegill
Electronic Publication