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In contrast, adelphophagy is the cannibalism of a multi-celled embryo. [1] Oophagy is thought to occur in all sharks in the order Lamniformes and has been recorded in the bigeye thresher (Alopias superciliosus), the pelagic thresher (A. pelagicus), the shortfin mako (Isurus oxyrinchus) and the porbeagle (Lamna nasus) among others. [1]
This phenomenon of embryonic cannibalism may play a role in sexual selection, as males compete post-fertilization for paternity. [16] Thus, intrauterine cannibalism in sharks may reflect not only sibling rivalry, but also male competition for successful mating with females, which is an example of sexual selection.
The largest and strongest embryos consume their siblings in the womb (intrauterine cannibalism) before each surviving pup is born. [6] It has one of the lowest reproduction rates of all sharks and is susceptible to even minimal population pressure , so it is listed as vulnerable and is protected in much of its range.
In the ocean food chain, large sharks generally only have to worry about keeping orcas at bay — but a new study suggests the apex predators may have to watch out for their own.. Researchers have ...
A female shark has hatched an egg without it being fertilised by a male, a zoo in Illinois has said. Brookfield Zoo said the hatching of an epaulette shark pup was not unusual, but the way in ...
The arrival of a baby swell shark at an aquarium in Louisiana has caused a wave of excitement, after the egg hatched despite the fact that no male sharks appear to have been involved.
Siblicide (attributed by behavioural ecologist Doug Mock to Barbara M. Braun) is the killing of an infant individual by its close relatives (full or half siblings). It may occur directly between siblings or be mediated by the parents, and is driven by the direct fitness benefits to the perpetrator and sometimes its parents.
In the course of pregnancy, the embryo's average rate-of-growth is 1.40 cm (0.55 in) per month until birth, when the shark pups are 40–60 cm (16–24 in) long, therefore, the frilled shark's gestation period can be as long as 3.5 years; [16] [15] at birth, a frilled shark's litter comprises 2–15 pups, with an average litter comprises 6.0 pups.