Questions tagged [ichthyology]

Questions relating to the study of fish or icthyology.

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5
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1answer
125 views

What are these animals, and what happened here?

While walking along the northern shore of Lake Ontario, I noticed the following strange scene: Here is a closer angle: What are these animals, and what is the likeliest cause of this?
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1answer
57 views

Is the fin of ray-finned fish live tissue or more similar to scales?

In ray-finned fishes, are what exactly are the fins made of? Is it modified skin, dead tissue like scale or nail on humans, or something completely different? Can the fin heal?
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33 views

In this aquponic tank, what are these three plants and could they be killing my beta fish?

I have a small aquaponic fish tank. In the tank there are two unknown types of water plants from a local pet store and the top there are three air plants from a local garden center. This tank was ...
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0answers
22 views

Are there taxonomic keys for members of the family poeciliidae in America?

I wish to know what are the taxonomic aspects necessary for the identification of certain species of poecilids, specifically what is the role in the counting of rays and spines and also the ...
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0answers
34 views

Is white fish + liver nutritionally equivalent to oily fish?

UK government nutrition guidelines say: Aim for at least two portions (2 x 140g) of fish a week, including a portion of oily fish My understanding is that the main difference between oily and white ...
4
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1answer
46 views

What is a lamprey's tongue derived from?

Tetrapods have tongues derived from the 2nd gill arch and nearby muscles. Lampreys are not tetrapods, and lack jaws, yet they have a tongue. What structure was this tongue adapted from?
3
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1answer
106 views

Can anyone identify this fish?

I saw it in the sea very close to the beach in front of Starfish Hotel in St Lucia. It had some spines along its back and it seemingly had fins on each side that split open into 4. It used its front ...
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2answers
89 views

Could the problem of overfishing be solved by throwing fertilized fish eggs at the right place and deepness into the sea? [closed]

I hear sometimes about over fishing and I wonder if the following idea could help to solve the problem. My idea is to throw fertilized fish eggs at the right place and deepness into the sea. These ...
2
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1answer
60 views

What Old World fish produces "white gems" in its brain?

In his ancient list of "white gems," Isidore of Seville mentions the "cinaedia," which he describes as follows: Cinaedia is found in the brain of a fish with the same name; it is ...
2
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0answers
45 views

Is it true that oxygen levels in water limits fish size?

This answer says that breathing water is inefficient, and that may act as a limiter to the size of fish. I've heard this in a couple of other places as well, but cannot recall the sources. However, ...
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0answers
19 views

Taxonomy and morphology of marine fish

is there a relationship between taxonomy and the presence of stomach in marine fish? In other words, are stomachless fish present in only certain phylogenies or are stomachless fish scattered ...
5
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2answers
98 views

Are there adaptations in tropical fish to compensate for less oxygen in water?

Warmer water means that the amount of gases- especially oxygen- dissolved in it reduces, since solubility of gases in a solution in most cases decrease with an increase in temperature. I'm interested ...
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0answers
73 views

How do schools of fish get enough oxygen?

Fish get oxygen from the water running over their gills, during which up to ~80% of oxygen is removed from the water. In schools of fish, how do fish swimming behind other fish get enough oxygen in ...
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2answers
220 views

How many Watt-hours can an electric eel produce in a day?

Electric eels are cited as being about to produce about 860 watts of energy. But I haven't been able to find information on how long they can sustain their charge. https://www.youtube.com/watch?v=...
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2answers
87 views

Is amphibians being descended from fish reflected in the animalia taxonomy?

I think it is common knowledge that amphibians are descended from fish. At some point there was a transition from sea to land. But when I try to confirm this through the Animalia taxonomy, the ...
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1answer
82 views

What fish is it?

I bought this 2 weeks ago, but i forgot to ask the seller, what fish is it. Currently the size is 1 inch.
4
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1answer
65 views

Can the extinct Chinese Paddlefish be revived?

I learned that a rare and unique giant Chinese Paddlefish recently became extinct. I'm wondering if samples of DNA were collected by scientists to allow reviving of the specie in the future. My quick ...
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0answers
31 views

Why are lungfish cartilaginous?

Lungfish have a cartilaginous notochord, and a reduced cartilaginous skull. Is this feature to improve flexibility, or is there another reason?
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0answers
37 views

How do fish persist in the upper parts of mountainous rivers with waterfalls?

I was recently traveling in a remote mountain region and hiking alongside a very small river. What caught my attention was the fish in the small ponds under the waterfalls. These ponds were just a ...
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1answer
389 views

What is the very hard sphere inside the eye of many common fish made of and how is it called?

Inside the eye of many common fish, like tuna, scad, snapper, actually probably all fish I have eaten, is a small sphere made of some very tough substance. This sphere is even hard to crush with teeth,...
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1answer
1k views

What fish is this?

I was out snorkeling at Biscayne Bay in Miami, Florida in the shallow waters near the shore when I saw this fish. What fish is this? I see it has black spots at the bottom and five white lines along ...
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1answer
49 views

How to calculate water pressure (Kpa/Mpa/PSI) with depth in the Biofloc fish farming?

Can you tell us a little bit about the water pressure (Kpa/Mpa/PSI) with depth in the Biofloc fish farming and the calculation of Kpa ​​/ PSI / Mpa so that one can understand which air pump machine ...
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1answer
52 views

How do fish transport egg to, and out of, coelom?

How do gametes get into coelom, and, later out of it? Excretion can be under quite heavy pressure, see https://www.youtube.com/watch?v=1OsRbuEINXI
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6 views

What external signals do tell catadromous fish to go from the sea to the rivers?

What signals do tell catadromous fish to go from the sea to the rivers? Is it photoperiodicity? Are there any other signals?
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0answers
91 views

What kinds of fish tend to have a rapid death after being caught?

I am asking this question because I am trying to make my diet less cruelty-oriented, for this reason this question can be related to trolley problem since I am coping with an ethical problem trying to ...
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0answers
99 views

Is it humane to kill fish by immersing them in very cold water or ice slurry?

I'm doing some research and advocacy for the humane treatment of wild-caught fish. Humane standards are more common on fish farms than at sea, so I am trying to identify some reasonable standards for ...
3
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1answer
47 views

Is there an adhesive that could used for larval fish?

I am currently working on an experimental design that requires a larval fish (~ 4mm long) to be affixed on a metal wire tip on its dorsal side. Now, I was thinking of a glue or adhesive to do the job, ...
3
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1answer
31 views

Which fishes produce alarm signals to warn other group members about in coming predators

Atlantic Goliath Groupers are fishes which produce unique low frequency sounds to mate and when approached by predatory fish . The sounds produced when approached by a predator (or even a scuba diver) ...
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42 views

DNA like marine animal or egg

What is the name of the marine egg or living being that is transparent like a jelly fish or a Venus girdle, with a shape like a DNA or better like a chain of infinites, long as half of a hand and ...
9
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1answer
156 views

What kind of fish is this white blue-stained fish?

This fish has been spotted at the Great Barrier Reef near Cairns (Queensland). I put a big effort to find it via Google but never could encounter anything similar. I have also made an attempt to find ...
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0answers
70 views

What type of fish is this

I saw this fish in an aquarium in a nearby house .I am not sure which species and sex this fish belongs to. [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/oOAZx.jpg
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2answers
163 views

Never caught this fish before

After catching a bunch of mangrove snapper using live shrimp, my son caught this fish in about a foot of brackish saltwater water off a dock near a rock wall in Vero Beach at around 10:00 AM on July ...
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1answer
47 views

What kind bottom feeder is this?

It’s about 2 1/2 inches long and had a little tail on the end. Also has short feelers that almost look like a moles.
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4answers
13k views

Can a person survive on blood in place of water?

This question: Can you get enough water by eating only fish? asks if a person could survive on fish alone. Can a person survive on fish and/ or blood alone of any species if stuck at sea or animal ...
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1answer
33 views

Formula for Oxygen Consumption for Atlantic Salmon (Mathematical) - insecurities regarding variable

The oxygen is calculated in mg per kg per something, so what does $h^{-1}$ stand for? hours maybe? The formula given below is an estimation of oxygen consumption for Atlantic salmon \begin{...
2
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1answer
55 views

Does the yolk sac for Danio rerio form at the vegetal pole?

Does the yolk sac in general form always at the vegetal pole? If so, is this the case for Danio rerio (the zebrafish)?
2
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1answer
160 views

What the name of this fish?

Well saw this on a fish group on facebook. Noone can give a decent answer so I came to you guys hoping you can help us? The one who posted lives in the Philippines and he said he caught it in the ...
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1answer
50 views

what is the name of this fish?

]2 fishes are of length 2 to 3 inches.
24
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2answers
4k views

What exactly is this small puffer fish doing and how did it manage to accomplish such a feat?

I recently saw a video on youtube where it shows a puffer fish making intricate designs in the sand: OZZY MAN VIDEO The puffer fish made this design on the sand: What exactly is the puffer ...
8
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1answer
977 views

What sort of fish is this?

Just saw a meme online with this fish on it. Is this a real fish? Can some aquatic expert identify this for us?
3
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1answer
76 views

Is the deep ocean fish look ugly because due to darkness there is no visual sexual selection? [closed]

Is the deep ocean fish look ugly because due to darkness there is no visual sexual selection? If so, is there a common notion of beauty between humans and animals?
2
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0answers
81 views

Did the Broadbill Swordfish population fully recovered?

Regarding the Broadbill Swordfish Xiphias gladius: I read Richard Ellis "Swordfish: A Biography of the Ocean Gladiator", Chicago University Press, 2013. The chapter about industrial-strength fishing ...
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1answer
78 views

What ecological niche do disk shaped fish exploit?

I looked up "Early Triassic" to get a sense of what that meant and I ended up on this image of marine life at the time. I noticed some disk shaped fish (#8 in the picture: Bobasatrania (durophagous ...
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0answers
129 views

Could fish safely "breathe" pure oxygen in their water?

I've heard it said various times before that humans can't breathe pure oxygen, or at least not for very long, before it would kill us. But during a discussion on Worldbuilding, the difference between ...
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1answer
51 views

anyone can help identify this aquatic microganisms?

I extracted from fish excretion and at 400x At the moment i have yet to try any medication because i don’t know what this is. Can someone who has seen this before share the light? thanks!
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1answer
99 views

What are the teeth of the viperfish composed of?

One of the viperfish's (genus Chauliodus) most unique traits is the transparent, needle-like teeth. Some other abyssopelagic fish (e.g. certain angler fish) have similar teeth. I'm curious as to what ...
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0answers
44 views

Who cleans the cleaner fish?

Cleaner fish are those fish that eat the dead skin cells and parasites off from other usually larger fish. ( such cleaners include wrasse, cichlids, catfish, shrimp etc ) I wondered if the cleaner ...
3
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1answer
163 views

Can anyone tell me what type of fish this is?

Notice the reflective patterns on its underside. I think it must be a deep water fish. It was found washed up on the ocean sand in Myrtle Beach, South Carolina (USA) after a hurricane.
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1answer
200 views

What kind of fish is on the picture?

I saw these fish in a video at an art exhibition, I'd like to find out what kind they are.
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1answer
89 views

Cichlid fish in Africa

Are the cichlid fish in Africa an example of divergent or convergent evolution? On the one hand they have evolved similar features to each other indicating convergent evolution, but on the other, they ...