Tag

Chimaeras

All articles tagged with #chimaeras

Ancient Ghost Sharks Dwell Deep, Pack Venomous Spines, and Survive the Abyss
science10 days ago

Ancient Ghost Sharks Dwell Deep, Pack Venomous Spines, and Survive the Abyss

Chimaeras, or ghost sharks, are ancient relatives of sharks that diverged about 400 million years ago; living mostly hundreds to thousands of metres deep, they swim with wing-like fins, sport rodent-like tails and rabbit-like teeth, and have venomous spines for defense. They hunt on the seabed for crabs, worms and urchins using electroreceptors, lay eggs, and males have a retractable tenaculum on their head to grip females during mating. They pose little danger to humans, but many species face extinction threats from overfishing.

Ghost sharks develop forehead teeth to aid in reproduction
science11 months ago

Ghost sharks develop forehead teeth to aid in reproduction

A study reveals that male ghost sharks have a unique forehead appendage called a tenaculum, covered in rows of teeth similar to those in their mouths, which is likely used for mating. This structure demonstrates the evolutionary reuse of oral teeth development for reproductive purposes, highlighting the remarkable adaptability of tooth formation in deep-sea fish.

Uncovering the Bizarre Genetics of Crazy Ants.
biology3 years ago

Uncovering the Bizarre Genetics of Crazy Ants.

Yellow crazy ants are the first known animal for which chimaerism is an essential aspect of life, according to a study published in Science. Males of the species are a mixture of two warring cell lineages, which is usually a developmental accident. The chimaerism has a crucial role in the ants’ caste system, contributing to the species' ability to evade ecosystems. The discovery raises questions about why the nuclei of some sperm fail to fuse with the egg nucleus, resulting in chimaeric males.