I went looking and was surprised by the amount of responses! When I typed in "what is an octopus baby called" I got 3,350,000 results! And the common belief is that they are first called octopus larva and then hatchlings lol so I dont think we are far from the mark. I still prefer inklets
I think early hatchling cephalopods are called paralarvae, particularly if they are planktonic. I assume this is because they are not, strictly speaking, 'larvae' because they hatch with adult morphology and never go through metamorphosis, so perhaps paralarvae was coined to get around that. Someone else might have a better idea of whether paralarvae is the general term for all ceph hatchlings or whether it is specific to certain species, though.
Development of cephalopods does not involve metamorphosis as in many marine invertebrates (Boletzky 1974). Young & Harman (1988), have proposed the term paralarvae, to be applied to cephalopods in the post-hatching growth stage, which is pelagic innear-surfacewaters during the day and has adistinctlydifferent mode-of-life from that of older individuals.
Octopuses of the family Octopodidae adopt two major life-history strategies. The first is the production of relatively few, large eggs resulting in well-developed hatchlings that resemble the adults and rapidly adopt the benthic habit of their parents. The second strategy is production of numerous small eggs that hatch into planktonic, free-swimming hatchlings with few suckers, simple chromatophores and transparent musculature. These distinctive planktonic stages are termed paralarvae and differ from conspecific adults in their morphology, physiology, ecology and behaviour. This study aims to review available knowledge on this subject. In benthic octopuses with planktonic stages, spawning characteristics and duration of planktonic life seem to play an important role in their dispersal capacities. Duration of the hatching period of a single egg mass can range from 2 days to 11 wk, while duration of the planktonic stage can range from 3 wk to half a year, depending on the species and temperature. Thus these paralarvae possess considerable potential for dispersal. In some species, individuals reach relatively large sizes while living as part of the micronekton of oceanic, epipelagic waters. Such forms appear to delay settlement for an unknown period that is suspected to be longer than for paralarvae in more coastal, neritic waters. During the planktonic period, paralarval octopuses feed on crustaceans as their primary prey. In addition to the protein, critical to the protein-based metabolism of octopuses (and all cephalopods), the lipid and copper contents of the prey also appear important in maintaining normal growth. Littoral and oceanic fishes are their main predators and defence behaviours may involve fast swimming speeds, use of ink decoys, dive responses and camouflage. Sensory systems of planktonic stages include photo-, mechano- and chemoreceptors controlled by a highly evolved nervous system that follows the general pattern described for adult cephalopods. On settlement, a major metamorphosis occurs in morphology, physiology and behaviour. Morphological changes associated with the settlement process include positive allometric arm growth; chromatophore, iridophore and leucophore genesis; development of skin sculptural components and a horizontal pupillary response.
The second reference is what I have thought to be the definition of paralarve but I had no clue for the benthic born (and the two species I have seen hatch actually sort of swim/hop about in the upper area of the tank for the first week before they settle). I noted that the O.briareus attained adult arm to mantle ratio very early but not quite at hatching. The O.briareus are, however, born with what appears to be a full complement of suckers along the arms but I did not note any observations on the mercs