October 2002 Issues Online June 2007 April 2007 February 2007 December 2006 October 2006 August 2006 June 2006 April 2006 February 2006 December 2005 October 2005 August 2005 June 2005 April 2005 February 2005 December 2004 October 2004 August 2004 June 2004 April 2004 February 2004 December 2003 October 2003 August 2003 June 2003 April 2003 February 2003 December 2002 October 2002 August 2002 June 2002 April 2002 February 2002 December 2001 October 2001 August 2001 June 2001 April 2001 February 2001 December 2000 October 2000 August 2000 June 2000 April 2000 February 2000 December 1999 October 1999 August 1999 June 1999 April 1999 February 1999 December 1998 October 1998 August 1998 June 1998 April 1998 February 1998 December 1997 October 1997 August 1997 June 1997 April 1997 February 1997 December 1996 October 1996 August 1996 June 1996 April 1996 February 1996 December 1995 October 1995 August 1995 June 1995 April 1995 February 1995 December 1994 October 1994 August 1994 June 1994 April 1994 February 1994 December 1993 October 1993 August 1993 Select any issue from the menu in this bar.

Ancient Survivors

Sieving through bucketloads of Bay-floor muck is not everyone's idea of glamorous research. For California Academy of Sciences marine biologist Rich Mooi, though, it's a quest for a lost species. His quarry: a tiny transparent "living fossil," Lightiella serendipita. Discovered unexpectedly off Point Richmond 49 years ago, the creature hasn't been seen since the 1950s, but Mooi and his team are determined to find it again.

Lightiella (named for U.C. Berkeley zoologist Sol Light) and its handful of relatives resemble some of the odd sea creatures of the 500 million-year-old Burgess Shale formation. Their group, the Cephalocarida, left no fossil record. But anatomical and genetic distinctions may make them the closest living kin to the common ancestor of shrimp, crabs, lobsters, barnacles, and all other crustaceans. "[Lightiella] fits so well what the reconstruction models suggest an early crustacean should look like that it remains an icon of living fossildom," says Mooi. Lightiella was only the second species of cephalocarid ever found.

Most crustaceans have a toolkit of limbs modified for feeding, locomotion, and defense. Lightiella, however, has generalized leaf-shaped limbs that propel water loaded with food particles into its mouth. It subsists on organic detritus that accumulates in

oxygen-poor sediments of harbors and bays. These 3-millimeter-long ooze-dwellers are sightless, but their neuroanatomy indicates an acute sense of smell. Unusually for crustaceans, each individual has both male and female sex organs and may be capable of self-fertilization. They're not prolific: specimens at Woods Hole produced only six young each year.

Mooi's search for Lightiella, part of the Academy's Bay 2K inventory of Bay invertebrates, has been unsuccessful so far. The neighborhood has changed; the Bay is full of non-native crustaceans and clams, and the pollutant load is heavier. But Mooi doesn't count these ancient survivors out: "They are probably still there, and given half a chance will be there for a long time, whether we can find them or not. Perhaps that's a secret to lasting this long. Stay out of the way of us 'flash in the pans,' and you can persist while we do ourselves in."

Contact: Rich Mooi (415)750-7086 JE

«To @@(newsletter_title)@@ Index

[ ABAG HOME | SFEP HOME ]

Copyright © 2002, San Francisco Estuary Project