100
votes
Can a person survive on blood in place of water?
Blood is not a good source of water.
1 liter of blood contains about 800 mL of water, 170 grams of protein and 2 grams of sodium (calculated from the composition of lamb blood).
When metabolized, 170 ...
- 8,049
32
votes
Accepted
Male and female seahorses: which is which
Seahorses are fish. Most fishes use external fertilization to reproduce (there are certainly exceptions, though), so there's not really any aspect of "giving birth" to sex definitions (that'...
- 44k
28
votes
A weird-looking fish with a shield
This is a species in the Peristediidae family, commonly called armored searobins or armored gurnards.
found in deep waters around the world, with most species in tropical regions. They are related to ...
- 29.7k
22
votes
What exactly is this small puffer fish doing and how did it manage to accomplish such a feat?
A tiny Japanese puffer fish creates a grand sand sculpture on the featureless seabed by using his fins to dig furrows. He uses this to attract the attention of passing females.
Why do puffer ...
- 1,562
18
votes
Can a person survive on blood in place of water?
You can drink blood of course to a minimalistic amount (eg- a few teaspoons ) and also if blood is free from pathogens. But it should always be in very small amounts and from suitable donor. Here's ...
- 559
16
votes
What exactly is this small puffer fish doing and how did it manage to accomplish such a feat?
This "nest" is created by a male pufferfish for both courtship and for rearing young.
The male puffer fish uses its body and fins (a combination of pectoral, anal, and caudal -- see here) to ...
- 29.7k
15
votes
Accepted
What sort of fish is this?
That is a blue parrotfish (Scarus coeruleus):
(photo: Marc Tarlock via Wikimedia Commons)
- 9,024
13
votes
What is the difference between the evolution of fins in whales and fish?
I agree with you that the question is ambiguous, and also that the most sensible answer would be C. However, one could make a more or less reasonable argument in favor of several other answers, too.
...
- 3,204
12
votes
Accepted
How can a tongue-biting parasitic arthropod become a fully functional tongue?
Short answer
There is no evidence whatsoever that the parasitic arthropod Cymothoa exigua develops itself into a functional tongue. Instead, it consumes the fish's tongue and occupies the freed buccal ...
- 52.3k
12
votes
Accepted
How long do fishes survive in a milk environment?
I can't support this answer with scholarly articles. But it's an interesting question if you think of milk as highly polluted water.
Water from a tap (which is what goldfish usually live in) is '...
- 24.7k
11
votes
Accepted
What kind of fish is this?
Its a Giant Gourami, Osphronemus goramy.
The giant gourami (Osphronemus goramy) is a freshwater species believed to be native to Southeast Asia, and has been introduced to other parts of the world.
...
- 8,784
11
votes
Accepted
Help identify these (two) fishes - Netherlands
The second fish looks like a rock gunnel (or Butterfish; Pholis gunnellus).
This is an eel-like fish found in the intertidal and subtidal zones of the North Atlantic.
Interestingly, the rock gunnel ...
- 29.7k
10
votes
Can a person survive on blood in place of water?
Here is a specific account of a person surviving at sea drinking turtle blood, while eating some fish and drinking some rain water.
Several peoples have a habit of drinking raw animal blood, at least ...
10
votes
Accepted
Identification of a strange skull
Looks like this is a neurocranium of a tuna or a similar species (dorsal view on this site).
I've also found a very similar picture of Atlantic blue tuna from USA, which seems to support that this is ...
- 431
9
votes
Accepted
Can prawns be classified as fish, or is their position ambiguous?
Introduction to phylogeny
What makes that two species being closely related or not has nothing to do with whether they look a like or whether they live in similar environment. It has to do with their ...
- 68k
9
votes
Can't identify this fish caught off NC coast
i think this is a frogfish. there is multiple types of this fish. i think this is an Ocellated frogfish. frogfishes related to anglerfishes. memorizing animals by classification eventually helps with ...
- 560
9
votes
Accepted
Worm found inside of wahoo
It is Giant Stomach Worm (Hirudinella Ventricosa).
It is a platyhelmith parasitic to Wahoo fish, feeding on its blood and found inside the stomach. It makes 98% of Wahoo's parasitic infections.
...
- 8,784
9
votes
Accepted
What fish is this?
I think this is probably a checkered puffer Sphoeroides testudineus based on your location and picture, with the wave-reflection patterning on the dorsal surface and ventral speckling the most obvious ...
- 44k
7
votes
Accepted
What are fish seeds?
Fertilized fish eggs are known as Fish seeds. In simple words, they are the baby fishes used for seeding new Ponds in fisheries.
They can be used in 4 stages:
Hatchling : Larvae stage where it have ...
- 5,192
7
votes
Accepted
What happens to deep sea creatures if they reach the surface?
It varies depending which creature is considered. The faster they are made to lower the pressure and raise the temperature, the worse the effects are. Some animals have a liver, which can help to ...
- 10.3k
7
votes
Why don't fish get hurt with so many sharp fish bones?
Connective tissues prevent fish from being hurt by its bones. They surround the sharp bones so that the bones do not hurt its organs/flesh.
However Of course the bones can hurt the fish, but the ...
- 253
7
votes
What are these animals, and what happened here?
That's likely a raccoon and a dead fish (salmon, perhaps).
For the animal on the left: notice the ringed tail, foot anatomy, and lighter foot color, and variable (light/dark) fur color:
University ...
- 29.7k
6
votes
Accepted
What is the difference between the evolution of fins in whales and fish?
Short answer
d) is definitely correct.
Background
The crucial element is that whales returned from land to the sea and re-evolved fins.
a) is incorrect, as the common ancestor may not have had fins. ...
- 52.3k
6
votes
Trying To Identify this Fish
It looks like a unicornfish (genus Naso), maybe Naso vlamingii, the Bignose Unicornfish. They're Acanthurids, related to surgeonfishes and tangs.
These are mainly found in Indo-Pacific ocean around ...
- 587
6
votes
Accepted
What kind of fish is on the picture?
This is an Atlantic wolffish (Anarhichas lupus). It's a very characteristic fish, with the teeth, the long dorsal fin and the small back fin.
https://en.m.wikipedia.org/wiki/Atlantic_wolffish
- 3,657
6
votes
Do schooling fish make sounds that predators could detect?
Yes, fish make sounds that predators can use:
Like us, fish produce sound both unintentionally and intentionally. Unintentional sounds from fish come all the time, resulting from hydrodynamic ...
- 24.7k
5
votes
Accepted
Do saltwater fish need to drink?
Short answer, yes. The fresh water concentration inside saltwater fish is higher than the surrounding sea water, and the salt concentration inside the fish is lower. This means that fresh water ...
- 470
5
votes
Accepted
Why isn't the biological niche occupied by whales instead occupied by fishes?
The "niche" of whales comprises much more than just being big. I would actually argue that this is just a byproduct of the marine lifestyle, since endotherms need to maintain their body temperature ...
- 1,244
5
votes
Accepted
Does anybody know what this shark is eating?
The fish in this image is Helicolenus dactylopterus. Shown below;
This fish, is more formally known as a Blackbelly Rose-Fish. This fish, is one of the Goblin Sharks' many prey in the deep sea.
In ...
- 404
5
votes
Do fish increase or decrease pH of aquarium water?
Like a glass of beer going flat, any excess CO2 that your fish produce will quickly and irreversibly escape into the atmosphere. Thus, at least in terms of the pH battle between NH3 and CO2 that you ...
- 3,781
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