The Darwin Centre

Phase One of the Darwin Centre in London's Natural History Museum is open. The vast collection of 22 million 'wet' biological specimens, including the entire collection of preserved molluscs, is no longer behind the scenes. In addition to gazing through the glass fronts of the side aisles from the main visitors' route, visitors can take guided tours, watch researchers and conservators at work and discuss the work with scientific staff in twice-daily seminars. Phase Two, which will house the 28 million insects and six million plants, is due to open in 2007.

More at: http://www.nhm.ac.uk/darwincentre/

Molluscivorous black carp faces ban in US

The US Fish and Wildlife Services proposes to add black carp, Mylopharyngodon piceus to the list of injurious wildlife. This would prohibit its importation and interstate transportation.

Black carp, which are native to China and parts of Russia and Vietnam, regularly grow to 3 ft and 35 lbs (and up to 5 ft and 150 lbs). The adults are exclusively molluscivorous, with powerful crushing teeth. Fish farmers use them to remove water snails which are intermediate hosts of fish parasites (yellow grub, Clinostomum margaritum, and Bulbophorus confusus). The parasites are transferred to ponds in the faeces of fish-eating birds.

Conservationists fear that the escape and establishment of black carp in the Mississippi basin would be disastrous for U.S. native mussels, 2/3rds of which are endangered, and U.S. water snails, which represent 15% of the World's species. The related grass carp has expanded into most of the lower states since 1963. Initially fish farmers used only sterile triploid black carp, but even a sterile black carp would eat 3-4 lb of mussels each day over an adult life span of more than ten years. Moreover, a breeding stock of normal diploids is needed to produce the triploids, and they could escape. As well as destroying snail and clam populations, the carp would compete with native fish, turtles, waterfowl and mammals, and encourage vegetation growth by removing the grazing actions of molluscs.

World's longest fossil nautiloid found by Arkansas students

From left: Prof Manger, Jonathan Gillip, Sarah Kee and Kevin Morgan in front of the 8 foot long nautiloid. Illustration to follow

Yards from a busy intersection in Fayetteville, three undergraduates from the University of Arkansas last month uncovered an eight foot long, 325 million year old actinoceratoid nautiloid. The site was known to bear abundant small ammonoids, but the students were initially looking for a three foot nautiloid supposedly located there. When geology student Sarah Kee noticed the calcite she called fellow student Kevin Morgan over, and the pair began to dig through the shale. They enlisted a third student, Jonathan Gillip, and continued digging. When the unusual size became apparent they contacted geology professor Walter Manger.

The only other nautiloid of comparable size (7 feet 2 inches) was also discovered in Fayetteville in 1963, again by students of the University of Arkansas.  Both nautiloids are Rayonnoceras solidiforme, which normally grew to less than 3 or 4 feet. Like modern squid, nautiloids died shortly after mating, but Manger suggests that these giant specimens may have suffered parasitic castration, and so lived much longer than normal, diverting energy to growth. Modern Nautilus show sexual dimorphism in the relative size of the apertures, and these giants also differ, suggesting one is male, the other female.

Located only an inch below the surface, the fossil could have been damaged or destroyed by the next hard rain.  Only the posterior end of the shell is missing. This was also missing in the 1963 specimen, and may have been eroded during life by boring organisms. The fossil has been placed in the University Museum.

Source: University of Arkansas: http://advancement.uark.edu/news/JAN03/cephalopod.html

Pygmy Octopuses

Many undescribed species of tiny octopuses are being discovered. Some of them weigh less than a gram and were previously assumed to be immature specimens.Most originate from tropical reefs. The realization that these were distinct species was first made from alcohol-preserved specimens in the Natural History Museum in Paris by Eric Hochberg (Santa Barbara Museum of Natural History). Dr Hochberg and colleagues Mark Norman and Mike Sweeney plan to present their findings at a conference in Thailand soon.

Source: New York Times, Sept 24, 2002, via molluscalist