[MortenS]

Inspired by the thread on parental care and male pregnancy in seahorses, I figured I should start a thread about oddities in the animal kingdom. Here is the place to describe animals that do things in a way most others don't.

Let me kick it off with a few extreme behaviours:

Homosexual traumatic penetration in Xylocoris maculipennis (L.)

Usually, males of Xylocoris maculipennis pierce the body wall of the female (thats why it is called traumatic penetration), and inject its sperm, which then swim around in the body until they encounter eggs and fertilize them.

Sometimes however, males inject sperm into the body wall of a male. The sperm then swims around until it comes to the victims testes, where they wait to be passed on to a female the next time the victim mates (Source: Introduction to behavioural ecology, Ed: Krebs and Davies)


Death before birth and extreme inbreeding
"Fifteen eggs, including but a single male, develop within the mother's body. The male emerges within his mother's shell, copulates with all his sisters and dies before birth."
" It may not sound like much of a life, but the male Acarophenax (I also see references to Adactylidium sp for the same story, not sure which is correct, but both are part of the same family) does as much for its evolutionary continuity as Abraham did in fathering children into his 10th decade"
- Quotes from Stephen Jay Gould, Pandas Thumb, "Death before birth of a mite"
My comments are in italics.

[Fishteacher73]

Parasitic Male in Deep Sea Anglerfish (Cryptopsaras couesi)

The males of this species are about the size of a kidney bean. They attach themselves to females(about football sized) and live as a parasite until the female is ready for breeding.

[Fishteacher73]

My personal favorite....It'll make you squirm the first time your read it...

The Vaudellia cirrhosa is a parasitic catfish. It usually ataches itself to the gills of other fish. (Fish exrete nitogenous wastes though the gills). It is this that attracts the catfish. There are many reports of the fish fining its way into the unknowing wader relieving himself. Up into the urethra...Its fins are spiked as to deter being pulled out. Have some good dreams about that one guys....

[MortenS]

Ouch...

I guess we can't forget that certain parasites alter their host behaviour:

The Lancet Fluke, Dicrocoelium dendriticum

Adults live in the bile ducts within the liver of various herbivores (cattle, sheep, goats and cervids). When eggs are laid (via feces of the host), the miracidia within the eggs must be eaten by a landsnail before development can continue. Inside the snail gut, the miracidium penetrates the gut wall and transforms into a mother sporocyst in the digestive gland. Daughter sporocysts are produced, which in turn turn into cercaria with stylets. Some months after infection, the cercaria start accumulating in the mantle cavity (="lung") of the snail, or on the surface of the body. They act as an irritant on the snail, and the snail surrounds them with mucus, and eventually deposit cercaria-filled slime balls.

Now the cercaria waits within the slimeball, until picked up by an ant (the common brown ant, Formica fusca is often the host). If the ant eats the slimeball, or feeds it to their larvae, they get infected by metacercaria. Over a 100 metacercaria may occur in a single ant. When the ant gets eaten by a herbivore, the cycle is completed.

Here comes the special part: One or two of the metacercaria in the ant travel up to the brain of the ant and encyst there. These are not infective, but they will alter the behaviour of the ant. Instead of returning home to the ant nest when temperature drops in the evening, infected ants will crawl to the top of grass or other plants, and attach to it with their mandibles. When they warm up in the morning, they resume normal behaviour.

This behaviour increase the chance that the metacercaria will enter the definitie host.

[Fishteacher73]

A bit off thread, Morten, but do you know if most flukes have an intemediate host in a snail? I have seen a few articles on fluke infestations of ornamental fish and the intermediate host for this specific one is a snail as well. (Also transmited by birds eating the snails and poopsing in the ponds).

[MortenS]

There are some variations, but snails are definetly a very, very common intermediate host of flukes.

For those that have only one intermediate host the pattern are usually like this:

Primary host: vertebrate
Intermediate host: snails (or clams in some instances) or crustaecean

For those with several intermediate hosts:

Primary host: Vertebrate (fishes, frogs, reptiles, birds, mammals)
First intermediate host: Snail
Secondary intermediate host: arthropods (e.g. insects, crustaceans), fish

[Fishteacher73]

My mind seems to have blanked on me, there is a term for this type of life cycle, (Various life stages only occuring in specific hosts), do you happen to recall what it is?

[alxian]

now admit it i'm sure some of you have hot sisters and you must of at some point wished you were a male Acarophenax.... (joking)

[alxian]

how about most australian animals?

i wonder what fossils lay under antartic ice.. dinosaur and mammalian alike. bound to be some odd critters. as odd as australian and south american creatures or even more odd..

does anyone know of any mainland expeditions scheduled?? i know that they are doing coastal research but thats not going to turn up much..

also what if AVP was more on the mark than the layman will give hollywood credit for and there are pyramids on the continent? what humans and lost civilizations could be found... i always liked the idea of russians using their huge orit mirror technology to melt sections of the ice (will include this in my novel ).

[MortenS]

Opps, wrong forum...I was posting in norwegian something that was going to a biology board I am on...

I'll save this space until I have something to write..I writing was about Monotremata btw..quite a coincident?