Development
Few specifics are known regarding the ontogeny of the vampire squid. Their development progresses through three morphologic forms: the very young animals have a single pair of fins, an intermediate form has two pairs, and the mature form again has one. At their earliest and intermediate phases of development, a pair of fins is located near the eyes; as the animal develops, this pair gradually disappears as the other pair develops. As the animals grow and their surface area to volume ratio drops, the fins are resized and repositioned to maximize gait efficiency. Whereas the young propel themselves primarily by jet propulsion, mature adults find flapping their fins to be the most efficient means. This unique ontogeny caused confusion in the past, with the varying forms identified as several species in distinct families.
If hypotheses may be drawn from knowledge of other deep-sea cephalopods, the vampire squid likely reproduces slowly by way of a small number of large eggs. Growth is slow, as nutrients are not abundant at depths frequented by the animals. The vastness of their habitat and its sparse population make procreative encounters a fortuitous event. The female may store a male's hydraulically implanted spermatophore (a tapered, cylindrical satchel of sperm) for long periods before she is ready to fertilize her eggs. Once she does, she may need to brood over them for up to 400 days before they hatch. The female will not eat towards this culmination and dies shortly thereafter.
Hatchlings are about 8 mm in length and are well-developed miniatures of the adults, with some differences. Their arms lack webbing, their eyes are smaller, and their velar filaments are not fully formed. The hatchlings are transparent and survive on a generous internal yolk for an unknown period before they begin to actively feed. The smaller animals frequent much deeper waters, perhaps feeding on marine snow (falling organic detritus).
Read more about this topic: Vampire Squid
Famous quotes containing the word development:
“If you complain of people being shot down in the streets, of the absence of communication or social responsibility, of the rise of everyday violence which people have become accustomed to, and the dehumanization of feelings, then the ultimate development on an organized social level is the concentration camp.... The concentration camp is the final expression of human separateness and its ultimate consequence. It is organized abandonment.”
—Arthur Miller (b. 1915)
“The experience of a sense of guilt for wrong-doing is necessary for the development of self-control. The guilt feelings will later serve as a warning signal which the child can produce himself when an impulse to repeat the naughty act comes over him. When the child can produce his on warning signals, independent of the actual presence of the adult, he is on the way to developing a conscience.”
—Selma H. Fraiberg (20th century)
“I can see ... only one safe rule for the historian: that he should recognize in the development of human destinies the play of the contingent and the unforeseen.”
—H.A.L. (Herbert Albert Laurens)