As the title says, what would be the largest animal where the offspring is wholly abandoned to fend for itself, as a matter of course, (at or before birth, post conception) by both parents?
Thanks.
I’m going to go with the Giant Squid here. The eggs and juvenals are found floating as plankton with nary a sign of an adult.
Is it fair to say no care ever takes place when, AFAIK, the giant squid has yet to be filmed or even witnessed alive in groups? I’m not sure.
As a further addition, is it fair to say that, in general, the larger the creature the more care it invests in its offspring?
Or has physical size little to do with the level of care offered by the parents?
Some varieties of aphids give birth to adult offspring, which means that they have given complete support to their children throughout their entire childhood.
I do not believe you could find a more devoted parent than that, except for my mother who still lets my brother live at home rent free despite his passing the age of majority several decades ago.
I don’t believe that physical size is the prime determinate of parental care. Mammals and birds tend to have higher levels of coddling for their offspring as compared to the normal reptile; reptiles tend to show more interest in their progeny than the average amphibian or fish; insects and mollusks show as wide a range of parental behaviours as all the rest of Animalia put together.
Perhaps you could define what you mean by parental care.
I have a feeling that this is correct (at least as far as mammals are concerned) - larger animals have fewer offspring per litter and therefore invest more time in rearing to ensure a greater chance of survuival…
I think that crocodiles abandon their eggs after laying and will eat their offspring if they encounter them after birth, so they could qualify…
Grim
Ok. I never considered the idea of animals giving birth to adult offspring.
What I understand by parental care is: the act of providing food, security and warmth for the offspring post-birth, until such times as the offspring is fully capable of supporting and protecting themselves.
But, what my query was really about is the opposite: which is the biggest animal who, giving birth to immature and defenseless offspring, leaves them to the mercy of nature to make their own way in life?
Oh, I see Grim slipped in a post before me.
Does the crocodile abandon its eggs in all cases? If so, its definitely a good contender.
No. Crocs build nests of compost, listen for the newly hatched infants, dig them out of the heap, and transport them in their jaws to safe water. I remember a photo in National Geographic many many moons ago of a cute little hatchling peering out through the teeth of its mother. The mother will stay in the nursery pool until the youngsters are less likely to be predated by birds and big fish.
From this page, on the mating habits of crocs:
So, they seem to not follow the standard reptile route of laying eggs and abandoning them.
IIRC, Komodo dragons would happily eat their offspring if they could catch any. They usually can’t, because baby Komodo dragons can climb trees and adults cannot. (I admit my source for this is Last Chance to See by Douglas Adams, but I don’t think he’d make up things like this.)
Well, regular squid just spawn and take off, so wouldn’t it be reasonable to assume that giant squid would behave the same way? After all, house cats and lions exhibit the same sort of parental behaviors, so why wouldn’t the various species of squid?
http://www.mbl.edu/publications/Loligo/squid/eggs.0.html
Other than that, what about whale sharks? They give birth to live young, and apparently don’t exhibit any parental care.
http://www.animalnation.com/Archive/aqua/sharks/wlshark.html
http://www.sharkresearch.com/introduction/shark_reproduction.htm
Mammals suckle their young, and so the baby animal has to be weaned before it can be left alone to fend for itself.
No mammal baby can live without its mother, so I would say that there can be no cases of mammal maternal abandonment, in nature, where the offspring could possibly survive.
Birds, reptiles and fish lay eggs; the more eggs a creature lays, the less likely it is to skick around and look after the brood. That is why large reptiles lay large numbers of eggs and then leave the eggs to their own devices. They are playing the evolutionary numbers game. Smaller reptiles and fish have external fertilisation, so they don’t even stick around for the conception.
Birds only lay a few eggs, in comparison, so their evolutionary drive compells them to incubate, protect and hatch the eggs and then nurture the offspring. (Unless the bird is a cookoo, in which case it lets other birds do the nurturing)
So really the answer boils down to the largest reptile vs the largest fish.
In that case, I would go for the leatherback turtle, if largest means heaviest, but if largest means longest, then it would surely have to be a crocodile of some sort
IIRC, all species of crocodilians exhibit some form of maternal care for their offspring. Guarding the eggs until they hatch, if nothing else. So, they’re pretty much out of the running, unless the fact that the males take off shortly after mating counts. But, I don’t think that’s the spirit of the question.
Leatherbacks are a definite contender for the non-fish category but, according to NOAA, Whale sharks don’t show any interest in their offspring, so I’d say the whale shark is probably the winner. CITE
Thanks all. (there’s no prize for the winner, except my thanks, sorry) 
Out of curiosity, how does a whale shark compare in size to the allusive giant squid?
(let’s define ‘size’ in this case as ‘the one that displaces the largest volume of water’).
Thanks again.
Okay, I see from photos that the giant squid is not quite the overwhelming beast of my imagination.
The whale shark it is, then.