49
votes
Accepted
How long can an octopus survive out of the water?
Short answer
Under ideal conditions, an octopus may survive several minutes on land.
Background
Octopuses have gills and hence are dependent on water for the exchange of oxygen and carbon dioxide. ...
- 51.2k
20
votes
Accepted
Identification of colorful jelly-like marine creature
You've found a sea anemone, a cnidarian of the Order Actiniaria. In this case, the anemone is closed and thus hiding its characteristic tentacles (likely as a form of protection while "out to dry").
...
- 26.7k
12
votes
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Spider identification
After some more searching, I think stumbled across the answer. It appears to be an…
Eriophora ravilla:
Source BugGuide.net.
This species appears to have quite a diverse range of colors, and ...
- 1,427
11
votes
Accepted
What is this long, thin and segmented insect I found in my house in India?
UPDATE:
Based on a comment by ArthurJFrost reminding me of the existence of a group of insects I totally forgot about, AND based on a closer examination of the cerci and what appears to be external ...
- 26.7k
10
votes
How long can an octopus survive out of the water?
Found an octopus today which had attached itself to a rock covered in algae during high tide and had failed to swim back out with the receding tide. We found it at low tide, this means it must have ...
- 101
9
votes
ID a shell from Puerto Rico
This is the shell of a marine mollusk called a chiton.
They are also sometimes known as sea cradles or "coat-of-mail shells", or more formally as loricates, polyplacophorans, and ...
- 26.7k
9
votes
Accepted
What are these tiny creatures swimming around my aquarium?
Hard to tell because of the poor picture/video quality, but almost immediately the body shape, distinct "face", size and behavior made me think of a small invertebrate animal called a ...
- 26.7k
8
votes
Can you identify this fossil?
It's a sea urchin (Echinoidea). It looks like a specimen of Lovenia or another genus from the heart urchin (Spatangoida) family.
What you see is just the shell without the spines.
Lovenia woodsii
...
- 2,048
8
votes
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What are these bladder snail parasites?
I have finally figured out what these are, and it turns out I greatly misunderstood their relationship with snails.
These worms are annelids of the genus Chaetogaster, specifically Chaetogaster ...
- 473
7
votes
Accepted
What is the largest species of polychaete?
According to the Smithsonian:
The longest of all known polychaetes was found in Port Jackson, Australia. It was a member of the family Eunicidae, consisted of approximately 1,500 segments and was ...
- 26.7k
6
votes
Accepted
Species identification - greenish blue ocean worm (nudibranch?) in Perhentian Islands, Malaysia
It's hard to identify from the photos provided, but I think it is Chloeia flava (a species of polycaete worm, within the phylum Annelida), also known in English as the "Golden Fireworm".
The size is ...
- 1,007
6
votes
Accepted
What happens to a snail if we cut off its antennae?
It really depends on which type of gastropod you are talking about, since different types of snails, have different types of eyes.
Marine gastropods could only become more mobile, when their ...
- 2,573
6
votes
Accepted
Why do Centipedes always have an odd number of pairs of legs?
Centipedes are part of the group of insects that utilize a short germ-band mode of embryonic development.1 One feature of this type of segmentation is that new segments are added sequentially to the ...
- 7,729
6
votes
Accepted
Identification of odd jellyfish-like creature in the Mediterranean
It seems to be a "Hula skirt siphonophore" - Physophora hydrostatica
Physophora hydrostatica, also known as hula skirt siphonophore, is a
species of siphonophores in the family ...
- 251
5
votes
Accepted
What kind of hot pink eggs are these?
Those appear to be the eggs of a species of apple snail in the genus Pomacea, probably the introduced invasive golden apple snail (Pomacea canaliculata), but there are at least two other candidates1,2....
- 5,296
4
votes
Did radial symmetry evolve twice?
Good question! I had never really though about it, so thank you!
Echinodermata have a pentaradial symmetry
Echinodermata actually don't have a radial symmetry like jellyfish do. They have a ...
- 67.6k
4
votes
Accepted
Why do crabs spit?
Breathing during digging
And if all that wasn’t enough responsibility for these claws, they also are used for digging. While most digging crabs use their back legs to burrow backwards into the sand, ...
- 2,573
4
votes
Accepted
What is the reason behind the subphylum name "Urochordata" for tunicates?
In 1877, Lankester proposed in "Notes on the Embryology and Classification of the
Animal Kingdom" division of the group we now call Chordata into three parts:
Urochorda
Cephalochorda
Craniata
which ...
- 8,759
4
votes
Accepted
What is this agglomeration of pink cells I found attached to a stone?
They are Apple snail's eggs; check the picture:
Check this.
- 357
4
votes
What is this agglomeration of pink cells I found attached to a stone?
This could very well be the eggs from an apple snail (family Ampullariidae).
According to Wikipedia
Several apple snail genera (Pomacea, Pila and Asolene/Pomella) deposit eggs above the waterline ...
- 26.7k
4
votes
Accepted
Species identification. Is this a leech?
Yes this is a leech. It appears to be a species in the family Glossiphoniidae, or the freshwater jawless leeches. This family of leeches is relatively flattened with a poorly defined anterior sucker.
...
- 26.7k
4
votes
strange creature
It is a penis worm!
https://en.wikipedia.org/wiki/Priapulida
Priapulida (priapulid worms, from Gr. πριάπος, priāpos 'Priapus' +
Lat. -ul-, diminutive), sometimes referred to as penis worms, is a
...
- 2,926
3
votes
Accepted
How do you determine the length of an annelid?
Leeches:
According to Taube (1966)$^1$:
The adults of American leeches range from about 1/4 inch to 12 inches in contracted length.
Because leeches can bloat to more than 10x their "normal"...
- 26.7k
3
votes
Accepted
Are there any theories why such an imbalance in chirality of molluscs?
Why so many molluscs exhibit sinistral winding?
The estimates of the number of molluscs vary quite greatly between 50,000 and 200,000 species. Of those molluscs species, about 70'000 are Gasteropoda. ...
- 67.6k
3
votes
Accepted
will an earthworm survive after covering its skin with a wet cloth
This is one of those speculative questions where you don't have a definite answer unless you specifically experiment and find out for yourself.
It is a known fact that earthworms breathe through ...
- 5,779
3
votes
Are there echolocating insects?
My understanding (as a PhD holder in toothed whale echolocation) is that insects do not use echolocation themselves as a means of hunting or sensing their environment more generally, but some do ...
- 129
3
votes
Do octopuses have better eyes than humans?
Adding to the answer above, another advantage of cephalopod eyes is the lower risk of retina detachment. (HumanEvolution)
Also, cephalopod eye focus image by moving the lense (like a camera or ...
- 31
3
votes
Help in identifying an unknown Golden Worm/Larvae
These are larvae of the so called fungus gnat of the order Diptera. Fungus gnats are small flying insects that look sort of like mosquitoes but they don’t bite. In fact, adult fungus gnats live only ...
Only top scored, non community-wiki answers of a minimum length are eligible