Classifying a creature

[Whitewings]

What might one call a warm-blooded animal that breathes water, bears live young, and then nourishes them on a fluid like milk?

[Khemehekis]

A hydromammal? A branchomammal or branchiomammal? A mammobranch?

[Salmoneus]

I'd call it a fish, assuming you're talkin about a type of fish. Bearin live youn has evolved repeatedly, so it wouldn't be odd for it to evolve among the cichlids (fish that feed their young with dermally-extruded mucous, i.e. milk). [fun cichlid fact: some species reproduce through fellatio...]

Alternatively, if you're talkin about a shark, I'd call it a shark. Sharks of course bear live youn, and althouh so far as I'm aware none produce milk, milk production, while much rarer than live youn, has also evolved several times, so a milk-producin shark would not be all THAT weird.

Or maybe, if you're talkin about an amphibian, you'd call it an amphibian. Some amphibians, such as the olm, or 'humanfish', retain gills even into adulthood; many amphibians bear live youn (although not the olm, as it happens). I don't know of any amphibians that secrete milk, but secreting chemicals throuh their skin is what amphibians are best at. Some caecilian amphibians do feed their youn solid skin secretions (i.e. dead skin), and apparently some live-bearin caecilians do indeed feed their youn with liquid glandular secretions... except they only do it while the young are still inside the mother's reproductive system, not once they've been born. However, it would be very plausible to have an amphibian that did all of these amphibian-y things (breathin water, bearin live youn, feedin youn after birth, and feedin youn with liquid glandular secretions) all in the same species.

Or maybe you'd call it an insect, if it were an insect. After all, some insects breathe water, and some have live young, and some at least secrete milk when the youn aren't yet born, so again, it wouldn't be that weird for a species to evolve that continued to do so after birth.

Or maybe you're tlakin about a spider, in which case, I'd call it a spider. I don't know of spiders that breathe water, but many of them do live on the water, so it wouldn't be that implausible. And of course spiders can feed their youn with milk and can bear live young, so...

Or maybe it would be a mammal. A mammal evolvin gills is indeed very unlikely, but I guess with enough time it might be possible!


Basically, I'd decide what your creature actually was, and call it that. The set of characteristics you list isn't specific enouh to narrow it down very much, because it could easily arise in almost any type of animal.


It's unlikely to be a bird, though.



EDIT: sorry, I forgot you said 'warm blooded'. That doesn't narrow it down much, thouh. Some fish are at least somewhat warm-blooded, as are some sharks. Icthyosaurs are thouht to have been both warm-blooded and live-bearin, as well as water-breathin.

[Khemehekis]

Some fish are at least somewhat warm-blooded, as are some sharks. Icthyosaurs are thouht to have been both warm-blooded and live-bearin, as well as water-breathin.

Yep. The opah is warm-blooded.

[Whitewings]

The concept is of an organism that bears live young and nurses them in a mammalian manner, and at the same time lives entirely in the water and breathes water. Imagine something akin to a mammalian ray or a ray-like dolphin.

[Khemehekis]

Question: Does this creature belong to a class of animals we don't have on Earth?

[Whitewings]

Question: Does this creature belong to a class of animals we don't have on Earth?

That is the intent. I'm trying to come up with non-Terrestrial life forms, but as the world is broadly Earthlike, the life is likely to also be vaguely Earthlike, though still quite different in at least some cases: the bird analogues have four wings and walk in a similar manner to bats or pterosaurs.

[Salmoneus]

Well if it only exists in a conworld, and isn't a member of any named class of animals, then it doesn't matter if you call it a 'blosh' or a 'shoblu', does it? How are we meant to answer that!?


I wasn't asking for an explanation of the concept - the concept is straightforward and fairly generic. My point is that there is no magical series of syllables to match that concept.

And I don't think it's helpful to call it 'mammalian', it which a real class of animals - and since the traits you discuss are also found among fish and sharks and amphibians and insects and spiders and probably other things too, it's not that useful to insist on them being 'mammalian'.

LOTS of animals breathe water and bear live young. Lots of animals bear live young and nurse them. Several animals breathe water and nurse their young. I'm not, as a layman, aware of a specific species that does all three (if one exists, my guess would be that it's either a cichlid fish or an amphibian), but the idea of such a species is so unremarkable and non-specific that "what would it be called?" is not a meaningful question.

[Shemtov]

If you're interested in presenting it to an audience, "filled whale/dolphin" might work.

[Whitewings]

Well, the idea was to collect ideas for how biologists might classify some of the native creatures, particularly the odder ones that don't really fit into Terran categories.

[Salmoneus]

But biology doesn't work that way. Biological definitions are cladistic, not based on superficial characteristics - so a biologist would find the most recent point of divergence from animals they knew, and put them in that category (if necessary inventing a new subcategory). So they could be birds, or even humans, for all we know.

[Whitewings]

That's fair, but it raises the question of how to classify organisms of another planet, at least until there's enough information available to start drawing up cladograms. I'm not trying to be obstinate, I'm trying to get a handle on the problem.

[svld]

They'll got their own classification after we've got enough information, no need to classify before that.