Questions tagged [invertebrates]

A paraphyletic classification for animals lacking a vertebral column.

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32
votes
2answers
90k views

How long can an octopus survive out of the water?

I saw videos of octopuses crawling on the ground and I was wondering how long an octopus can survive when out of the water? Does it depend on either its size (i.e., does a big octopus from deep sea ...
20
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1answer
658 views

What are these bladder snail parasites?

I collected some bladder snails several months ago. While checking them out one day, I noticed that they were now infested with worm-like ectoparasites. Appearance and behavior Here's a picture of a ...
20
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2answers
289 views

Selection for less efficient egg transfer in Human Botfly life cycle

I have heard that the Human Botfly transfers its eggs through other invertebrates, and it strikes my curiosity that if an insect could simply land on its host directly to deposit its eggs, then why ...
15
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1answer
4k views

Why do crabs spit?

Last year I photographed this juvenile Sally Lightfoot Crab (Grapsus grapsus) 'spitting' (click for larger view): I thought I'd look up more information on this behavior, but couldn't find any ...
14
votes
2answers
2k views

Can you identify this fossil?

I found this fossil near a beach in Victoria, Australia. Can anyone identify it? It is roughly the size of an Australian 20 cent piece (~30 mm). I think it might have been washed down from an eroding ...
14
votes
1answer
708 views

Identification of colorful jelly-like marine creature

I'm on my trip to Gulangyu Island, Xiamen, Fujian Province, China. Today(4th February 2017), at 12:13 A.M., I saw a beach filled with huge rocks on which various dry shells reside. Among the shells, I ...
9
votes
2answers
3k views

Spider identification

This red spider has set up a web in my yard, in South Eastern, Texas, United States: The spider itself is about an inch long (2.5 cm), and is predominantly red to brown in color, with red legs, and a ...
9
votes
3answers
981 views

Are there echolocating insects?

Echolocation is the ability to obtain spatial information of the surroundings from echos generated by the animal. There are bats and other vertebrates that naturally use it. I was wondering if this ...
8
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1answer
4k views

What biological constraints are there on how large a spider can grow?

Spiders fascinate me, but what intrigues me the most is just how big some spiders can get, which leads me to my question. What biological constraints (if any) would limit how large a spider could grow,...
8
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1answer
606 views

ID a shell from Puerto Rico

I recently found this in Rincon Puerto Rico on the beach. I assumed it was a baby sea turtle shell or some kind of turtle. Someone that frequents Puerto Rico said it was not. Does anybody know what ...
8
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1answer
2k views

Aquarium snail identification

Many of these little snails suddenly appeared in our aquarium from nowhere. I suspect that some snail eggs hitched a ride with some recently purchased plants. Can anyone identify the species? I am ...
8
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0answers
166 views

What is this underwater creature?

West Bali, about 10 meters deep. Body is roughly 10 cm across. Does not move.
8
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1answer
150 views

Is the number of legs in myriapoda determined entirely by the genome?

Myriapoda (comprising, among others, millipedes and centipedes) can have hundreds of legs (Illacme plenipes having up to 750 legs). Interestingly, the number of legs (or leg pairs) appears to differ ...
7
votes
1answer
92 views

Which poison makes seastars inedible to possible predators?

In the new citizen science project (see: Sea Floor Explorer), numbers of seastars, scallops, crustaceans and other animals are counted. Already one can see a heavy bias in favor of seastars, both the ...
6
votes
1answer
341 views

What is this strange horned, slug-like coral reef dwelling creature?

On the first episode of BBC's Blue Planet II they visited a coral reef and showed some odd reef-dwelling creatures as part of their establishing shots, but they did not identify the creatures. What ...
6
votes
2answers
11k views

Do octopuses have better eyes than humans?

I've read that unlike humans, octopuses have eyes "designed" the "right way", i.e. with the nerve fibers behind the retina, thus getting rid of the blind spot we humans have as well as theoretically ...
6
votes
1answer
265 views

Are there any theories why such an imbalance in chirality of molluscs?

Most gastropods exhibit sinistral (right hand) winding of their shells. But very few species are anti sinistral. Have there been any theories as to why such a great difference?
5
votes
1answer
432 views

What are these tiny creatures swimming around my aquarium?

I was checking out my aquarium today, and decided to scoop out a water sample and take a look at it more closely. What I discovered were numerous, very, very tiny white worms (?) swimming around in ...
5
votes
1answer
96 views

Anyone know what this it?

More than 1 washed up on a beach in Ireland..close to some big jellyfish
5
votes
1answer
971 views

Species identification - what kind of worm is this?

I am finding these worms in my bathroom since summer arrived. I have been finding these on floor, walls and damp towel I left hung overnight in bathroom couple of times. When these worms are squished, ...
4
votes
2answers
90 views

What is this agglomeration of pink cells I found attached to a stone?

Photo taken in a garden in Singapore. The organism is attached to a stone, close to water. Many of these were there. Size approx 3cm. The shell of this eggs is very soft. When touched, a pink ...
4
votes
1answer
347 views

What is the largest species of polychaete?

My Google searches seemed to avail no results. My question is: What is the largest living species in the class Polychaeta? That's about it. I understand that there will be few accessible weights for ...
4
votes
1answer
233 views

Species identification - greenish blue ocean worm (nudibranch?) in Perhentian Islands, Malaysia

We found this on a beach at the Perhentian Islands, Malaysia in March, 2016 and cannot identify it. It's some sort of worm-type creature with many legs and bluish back about 15cm long. The legs ...
4
votes
2answers
1k views

Did radial symmetry evolve twice?

In the history of animal evolution, both the Cnidarians and the Echinoderms have radial symmetry, according to this cladogram: Source: http://www.cpalms.org/Public/PreviewResourceLesson/Preview/45851 ...
4
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0answers
193 views

Do invertebrates dream? [closed]

From Wikipedia: Studies have observed dreaming in mammals such as monkeys, dogs, cats, rats, elephants and shrews. There have also been signs of dreaming in birds and reptiles. Have there been ...
3
votes
1answer
125 views

Identification of a small flat bug

So for the last few days I have been noticing these small bugs in my bathroom -- they don't appear frequently, and I see them once or twice a month. The characteristics and behavior I observed are as ...
3
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1answer
312 views

Sex determination in cephalopod?

I see some source say octopus do not have sex chromosome. So what's the sex determination mechanism for cephalopods?
3
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1answer
451 views

Swarming red millipedes found near my home

Location:Hyderabad,South India. These worms usually come out when it rains,these worms are the most common ones any help in figuring out them,they come in groups too.
3
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1answer
174 views

Which kind of caterpillar is this?

Which caterpillar is this? It was found in mid Europe during this time (April). Size about 2cm in length.
3
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0answers
49 views

How do insects recognize their host plants?

Many insects, like butterflies have specific host plants on which they feed or lay eggs. While researching about some butterflies, I found that they lay their eggs on certain specific plants and their ...
3
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0answers
72 views

Are baby centipedes poisonous like the adults?

I know that centipedes have an appendage called "poison claw".But I am not sure if the same is there in the baby centipedes and if its functional like that of the adults. So are baby centipedes ...
2
votes
1answer
77 views

Species identification. Is this a leech?

The pictured creature, shown at the bottom of a glass, was attached to a friend’s child after he was swimming in the Ottawa River today. It stretches out to roughly an inch in length but in this “...
2
votes
1answer
166 views

What is the reason behind the subphylum name “Urochordata” for tunicates?

There are two major invertebrate subphyla of the chordates (phylum Chordata): Cephalochordata (the lancelets) Urochordata, aka Tunicata (the tunicates) My understanding is that the cephalochordates ...
2
votes
1answer
133 views

How do you determine the length of an annelid?

I'm currently studying a horse-leech, and would like to know if it is fully grown or not. When I read about different annelid species a maximum length is often given, so I wonder if there is some ...
2
votes
1answer
136 views

will an earthworm survive after covering its skin with a wet cloth

I am very curious about this question. I got this doubt when I was studying anatomy and physiology of the earthworm Lampito mauritii. It breathes through its skin (cutaneous respiration) and if we ...
2
votes
2answers
66 views

Bug Identification: Tiny Bugs in Fairport NY

We have been finding a ton of these tiny bugs (pin head size or smaller) outside on our patios, outdoor tables, on the grill, etc. What are they and how do we get rid of them?
2
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1answer
60 views

Help with jellyfish species identification

Our research group (Evolutionary Genetics Group, University of Zurich) has received a letter from a special needs child who has kindly asked us to identify three jellyfish species. Unfortunately, the ...
2
votes
1answer
249 views

Do hornets remember and recognize a human? Do they have any (kind of) memory?

hornetology So it happens that a hornet (vespa crabro) flew inside my house today and now is being held in a plastic container (I made some holes to let it breathe). But it also happens not just this ...
2
votes
1answer
192 views

What is this discarded exoskeleton from?

This morning I was looking round the garden and found this sticking out of a pit in patch of soil, next to the wall of the house (in a trough sort of thing). I came to the conclusion it must be part ...
2
votes
1answer
40 views

Which is the guideline to choose a molecular target to identify vertebrate hosts from arthropod bloodmeals?

There are some molecular targets to identify vertebrate hosts from arthropod bloodmeals including the Cyt b gene and the COI gene. Which are the standards or characteristics that I have to bear in ...
2
votes
1answer
189 views

Help in identifying an unknown Golden Worm/Larvae

Can anyone help me to recognize this type of species? Is it a clustered worms or clustered larvae? Location is in Bali, Indonesia. Recently this species is goes viral, but people here always link this ...
1
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2answers
319 views

Cockroach brain functional anatomy

In insects like the cockroach the brain is distributed, i.e. some parts lie in the head and some in the abdominal cavity. Which part is responsible for controlling locomotion?
1
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1answer
53 views

Im trying to find out what type of snail this is

The snail is pretty large and located in texas.
1
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1answer
103 views

Help in identifying marine specimen?

I came across this specimen which I assume belongs toeither the phylum porifera or to the coelenterata. Can someone please help me identify it? The specimen was found in Ayodhya, India.
1
vote
1answer
756 views

What is the role of gills in terrestrial Crustaceans?

Why do Crustaceans that live on land have maintained their gills? In aquatic species, the gills play a pivotal role in respiration, but terrestrial crustaceans have tracheal lungs. So why do they have ...
1
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0answers
25 views

Effect of myelination on inteligence in cephalopods

Cephalopods are known for their unique intelligence compared to other invertebrates. The number of neurons of cephalopods is of the order $5*10^8$, similar to dogs. Humans have about $10^{11}$ ...
1
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0answers
41 views

Can anyone please identify this?

We saw this leech like worm in Kerala, India. Can anyone identify it for us? I saw it today, 10th September. It's about 6 to 7 centimeters long. It was very still, didn't move while we went close and ...
1
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0answers
27 views

Carbon Dioxide, sea water, diatoms, and oxygen

I recently viewed a documentary called “Flying River Observed in Tallest Structure in South America, National Geographic” (https://www.youtube.com/watch?v=HjpPsZTwsaM). In this film, as an aside, it ...
1
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0answers
53 views

What kind of sieve does one use to extract meiofauna?

Suppose I have a core of sediment, and I want to extract the meiofauna from it, in order to study these organisms. According to the sources I could find, this involves using a very fine (e.g. 45 μm) ...
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0answers
33 views

How did craniates evolve?

Looking at most chordate phylogenetic trees, it seems that we usually have something like this: ...