The biological study of animals.

learn more… | top users | synonyms (1)

1
vote
1answer
286 views

Identifying structures from anterior end of dissected prawn

Note: This image might be disturbing. I want to know what the red and the black structures (directly posterior to the red structure) are. I guess it's the heart.
0
votes
1answer
871 views

Identifying internal structure of dissected prawn

Note: Some of the images might be disturbing. I have dissected prawn for the first time. Would like your help in identifying some structures . This is the dissection of the posterior part of the ...
3
votes
1answer
110 views

Identifying internal structures of dissected fish

Note : Images displayed below might be disturbing to some people. I have dissected a fish for the first time ! I have some idea of what some of the structures might be but I am not sure and so would ...
1
vote
1answer
463 views

In an open circulatory system, how is blood moved?

In the mollusks section, the powerpoint mentioned that gastropods and bivalves have an open circulatory system. According to the note, this means that the blood does not travel in vessels. How, then, ...
4
votes
2answers
118 views

Can I force evolution in a group of cells by removing all the smaller cells?

I actually have algae growing in water in a container. I was thinking if it was possible to filter the water so that all the small cells will be filtered out and only the bigger ones will remain to ...
5
votes
3answers
389 views

Why are there ecosystems?

Why would things self-organize in such a manner? I'm a mathematician and I have no baggage in ecology or biology. If the question is too broad maybe someone can point me to formal sources where this ...
1
vote
1answer
132 views

List of the biggest companies that work in selective breeding

Looking at this question, I've been wondering, What are the biggest private companies which work in both animal and non-animal selective breeding? Let me know if Biology.SE is not appropriate for ...
3
votes
1answer
96 views

Book recommendation on selective breeding?

I am looking for a good book that gives a nice overview of the science and technics of selective breeding. I am particularly interested in the use of population genetics to support decision in this ...
5
votes
1answer
75 views

Burns' “To a mouse” - what species of mouse?

What's the most likely mouse species Robert Burns is referring to in his poem "To a Mouse, on Turning Her Up in Her Nest with the Plough". Burns farmed near Ayr, which is on the Firth of Clyde in ...
2
votes
1answer
96 views

Do chicks in eggs excrete?

I want to know if, as a baby chick grows inside the egg, does it excrete waste? If it does excrete waste, does the waste just sit inside the egg with the chick, until the chick cracks open the egg ...
9
votes
1answer
202 views

Are there specific features of birds that cats/small predators are attracted to?

I've recently heard a podcast, in which a professor describes one of the theories as to why we like abstract art. In his talk, he mentions an experiment with seagull chicks, in which the seagull ...
2
votes
0answers
56 views

How did the roar evolve from snort?

When Lions roar, or Dogs show aggression, they do that snort-roar thing. They're producing sound while inhaling. How did that come to be when all (?) other forms of sound involve exhaling? Humans do ...
3
votes
2answers
426 views

What is the fastest marine mammal?

When I did a research, most of the sources say that orca is one of the fastest. But I could not find a source that says it is actually the fastest. Some sources say that Dall's porpoises rival orcas ...
8
votes
2answers
469 views

Why is Portuguese man o' war considered a colony?

The wikipedia entry on the Portuguese man o' war says: ... the Portuguese man o' war is ... not actually a single multicellular organism but a colonial organism made up of many highly specialized ...
0
votes
2answers
212 views

Why can we breathe only oxygen?

Plants has the capacity to take in both CO2 and oxygen, that's during day CO2 and at night oxygen. Why don't humans have such a capability?
2
votes
2answers
67 views

Maintaining purebred pedigrees and how to lessen chance of getting disease?

Many breeds of dogs are known for a high incidence of genetic disorders. German shepherd and Saint Bernard dogs are predisposed to developing a crippling condition called hip dysplasia. Q: What ...
16
votes
3answers
2k views

Are humans the only animal that requires “clean water”?

I've seen a number of animals - dogs, cats, squirrels, ducks and geese, etc drink from puddles, some of them were muddy, others had green flora growing under water. Same goes for lakes and rivers. A ...
4
votes
1answer
329 views

Sexual selection in cats or other animals

I was wondering if you could answer some of my questions regarding sexual selection in cats (or any other animals). I would like to apologize beforehand for my incorrect term use. When it comes to ...
1
vote
1answer
84 views

Are these bat social calls?

I'm currently researching bat social calls (not echolocation calls) and have been given a series of samples (in .wav format) and wanted to know, if what I can hear is actually the social calls. Below ...
1
vote
1answer
59 views

Clownfishes and Sea anemones

Relation between clownfishes and sea anemones is a classic example of mutualism. I wanted to list the species of sea anemones that are involved in this mutualism but I got lost.. Could you help me ...
8
votes
1answer
125 views

Dogs bark at familiar person in Santa costume. Why? Don't dogs trust smell over vision?

Last night 10 humans and 2 dogs spent Christmas together. At some point, one human dissappears for a few minutes and comes back wearing a full Santa outfit. Upon respawning, the dogs start barking ...
1
vote
0answers
27 views

Temporal effects on pathways? [closed]

I was wondering whether or not there exist certain pathways that are triggered by a temporal signal. We're almost at the winter solstice now. Does animal or plant function involve signals that are ...
1
vote
1answer
64 views

Can pets catch the cold?

Last night I was drying my cat with a towel after shenanigans in the rain and she sneezed! Questions Can cats/dogs/hamsters or other pets catch the cold? How quickly do they recover?
5
votes
2answers
105 views

The least complex animals with ability to dream

People can dream, dogs can dream, cats probably too when they are sleeping. What about other creatures? Can a bird dream? Do rats have dreams? Are there any studies about that kind of thing? What ...
2
votes
1answer
339 views

What are the visual, behavioral similarities and differences between Yellow Fever Mosquito (Aedes aegypti) and the Tiger Mosquito (Aedes albopictus)?

The Tiger and Yellow Fever Mosquito visually look very similar. Recognizing the difference is important for tracking and controlling the spread of Yellow Fever, Dengue fever and other diseases. ...
2
votes
1answer
586 views

Excretion of various wastes and water requirement

A common fact is that Ammonia, Urea and Uric acid are the most common excreted metabolites and their removal needs varying amount of water, highest for ammonia (hence suited only for aquatic animals) ...
2
votes
0answers
72 views

Organisms with the most extreme sensory capabilities? (sight, smell, sound) [closed]

Background It is quite mind boggling to imagine what it would be like to be missing sight, sound, touch, smell, taste etc. Question Which organism holds the record for most extreme sensory ...
4
votes
2answers
2k views

The number of nipples (breasts) a species has?

Only mammals have mammaries and mammary glands. What evolutionary factors determines the number of mammaries (nipples/teats/breasts) a species has? Is it always an even number?
1
vote
1answer
2k views

Cats, Dogs and Bears - how are they related?

What is the ancestral relationship between cats, dogs and bears? I presume they are more closely related to one another than other paraphyletic clades of mammal. Which came first? What did their ...
4
votes
2answers
217 views

Do animals suffer from “Human” mental disorders?

It is tragic, but apparently Killer whales and Dolphins can commit suicide too (e.g. here)... This suggests they can become depressed. I wondered whether they were "clinically" depressed like many ...
4
votes
1answer
247 views

Body size, what are the evolutionary trade-offs?

Background Considering just the "Kingdom Animalia" branch of organisms. It is clear that bigger does not necessarily mean better - there is large variation in body size... From the 94 µm long ...
1
vote
1answer
166 views

Can anyone identify this caterpillar / cocoon?

This insect is about 0.5 mm in length, so it is very small. It doesn't have legs I don't believe, I am not too good at this but I don't know if it's a worm or more like a cocoon for something. I do ...
3
votes
2answers
202 views

Are these cats calico?

Calico cats are cats that have 3 fur colors and are always female or males two X chromosomes. I've seen many cats that will have 2 fur colors (one of them is usually white) and another, third, color ...
0
votes
1answer
212 views

What are the universal laws of Nature concerning animals' behaviour? [closed]

I'm looking for very old (centuries) treaty or recent (20 & 21th century) research that state what some of the laws of Nature are, particularly concerning wild animals' behaviour. Such as; every ...
1
vote
1answer
86 views

Niche overlap Index

I wanted to use the compana() function from the adehabitat package. I don't really understand the meaning of the data in the ...
2
votes
1answer
1k views

Do bigger animals have more testosterone?

I was wondering the other day outside, thinking about varieties of species and their aggression levels, etc. I had a theory that since these highly aggressive, powerful, and viciously advantageous ...
5
votes
2answers
178 views

Transitivity of Species Definitions

There are many definitions of "species" which usually take the form Two individuals are of the same species if ... An implied (rarely made explicit) property of any sensible species definition ...
0
votes
1answer
74 views

Function of carapace

Majority of crustacean larvae have expanded carapace drawn out into processes as an adaptation for : a. Protection from enemies b. Planktonic habit The answer given is b but I think it should be ...
1
vote
1answer
118 views

Why would the Camargue horses have a white coat while the foal have a dark coat?

The current issue of the magazine Lonely Planet India(Oct 2013) presents a photo of Camargue Horses which are white coated and mentions that they are born with dark hair. A search shows that the foal ...
3
votes
1answer
94 views

Will a garter snake eat unusual prey if made to smell like something normal?

I have noticed that my garter snake only eats after it has smelled it's prey to make sure it is a slug, and it doesn't matter whether it's moving or not. If I were to coat, say, a caterpillar with ...
4
votes
1answer
127 views

Identification of this Salamander

This salamander was found in a small forest pond somewhat near the Oregon coast. In the area are many rough skinned newts and a small number of another type of salamander that I still can't find the ...
3
votes
1answer
80 views

Fear in elephants

It has been noted that elephants trained for war, as was done occasionally in earlier times, have still shown a tendency to panic in battle much more often when compared to a war horse trained for the ...
2
votes
1answer
696 views

Why are urban birds still scared of humans?

I understand that animals are naturally scared of humans because we basically slaughtered every living thing we found in our way for millennia. How long does it take for them to genetically 'forget' ...
2
votes
1answer
57 views

Can a chicken's lard become liquid depending on its diet?

On Cooking.se, somebody asked a question about the fat in chicken stock sometimes being liquid and sometimes solid once the stock has cooled. The only answer until now suggests that the difference is ...
2
votes
0answers
44 views

What's behind the amazing colour combinations in pests & insects?

What's behind the amazing colour combinations in pests & insects ? Do this colour combination signals any character/ poison of the pest/insect ?
3
votes
0answers
187 views

how much grass does a sheep eat in square meters per day? [closed]

I want to buy some sheeps in order to eat my garden's grass. How much grass does a sheep eat each day ??
2
votes
0answers
73 views

Where are the gastralia (stomach ribs) attached?

Crocodiles and some dinosaurs have a second set of ribs between the sternum and pelvis called gastralia. Where are the gastralia attached to the rest of the skeleton?
12
votes
4answers
5k views

Why we have no enzyme to digest cellulose?

As we know, cellulose is the most abundant polysaccharide in nature. Why don't we have any enzyme to digest cellulose?
1
vote
0answers
43 views

Does sleep duration vary for animals based on time of the year?

I'm interested in the sleep patterns of wild animals, that still use sun for controlling their biological clock. Animals entrain their biological clock to the day/night cycle using light as the ...
4
votes
2answers
111 views

What animal's lower eye lid moves to upper one when closing eyes?

I know cock's lower eye lids moves to meet the upper one when it closes its eye. What other animals does this? BTW, "cock-eyed" can mean upside down, I think.