10 new species of freshwater earthworms

Scientists have discovered 10 new species of semi-aquatic freshwater earthworms in river systems in Thailand.

According to a report published in the journal "ZooKeys", the earthworms in the genus Glyphidrilus occur in a wide range of natural freshwater habitats which include rice fields, where they might play an important role in the development of organic farming.

The newly-discovered worms have a rounded body tip, while the end is square shaped. When twisted, the posterior end, which is normally above the soil surface, forms U-shaped channels. These are used to allow water circulation down the burrow.

This is probably an evolutionary adjustment that ensures oxygen transport to the deeper surface of the worms, while their bodies remain in the burrows.

Another peculiar feature are the so-called “wings”, or the expanded part of epidermis near the body tip. The function of the wings is still unknown to scientists, but it has been suggested that they evolved to assist breathing in such aquatic habitats.

New species of crab discovered in the Philippines

 

Four new species of crab have been discovered in the Philippine island of Palawan. And one of them has an unusually bright purple shell.National Geographic reports that the crab may use its uniquely colored shell to help identify its own kind."It is known that crabs can discriminate colours. Therefore, it seems likely that the colouration has a signal function for the social behaviour, e.g. mating," Hendrik Freitag of the Senckenberg Museum of Zoology in Dresden, Germany told AFP."The particular violet coloration might just have evolved by chance, and must not necessarily have a very specific function or reason aside from being a general visual signal for recognition,"said  Freitag. Freitag's report on the new species of crabs was published in the Raffles Bulletin of Zoology.The crabs are quite small in stature, each from about an inch to two inches wide.

While many species of crab are known by their red rust hues, some differently colored crab species are quite popular around the world, perhaps most notably the Chesapeake blue crab.

Freitag said the purple crabs likely have several natural predators, including some humans in remote areas. But he said the greatest threat to the species is ongoing forest clearing for farming, mining and home building.