A new poecilogonous species of sea slug (Opisthobranchia: Sacoglossa) from California: comparison with the planktotrophic congener Alderia modesta (Lovén, 1844)
1 Department of Biological Sciences, California State University, Los Angeles, CA 90032-8201, USA; 2 Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 90093-0202, USA; and 3 Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007, USA
Correspondence: P. J. Krug; e-mail: pkrug{at}calstatela.edu
 |
Abstract |
|---|
Cryptic species are increasingly recognized as commonplace among marine gastropods, especially in taxa such as shell-less opisthobranchs that lack many discrete taxonomic characters. Most cases of poecilogony, the presence of variable larval development within a single species, have historically turned out to represent cryptic species, with each possessing a single canalized type of development. One well-characterized example of poecilogony was attributed to the sacoglossan opisthobranch Alderia modesta; in southern California, slugs resembling this member of a monotypic genus produce both long-lived, planktotrophic and short-lived, lecithotrophic larvae. Paradoxically, however, A. modesta is exclusively planktotrophic everywhere else in the northern Pacific and Atlantic Oceans. A recently completed molecular study found that slugs from poecilogonous populations south of Bodega Harbor, California, comprise an evolutionarily distinct lineage separate from northern, strictly planktotrophic slugs. We now describe the southern species as A. willowi n. sp., based on differences in morphology of the dorsum and radula, characteristics of the egg mass, larval development mode and nuclear and mitochondrial genetic markers. A DNA barcode is provided, based on 27 fixed differences in the cytochrome c oxidase subunit I gene that can reliably differentiate Pacific specimens of Alderia species. Genetic and morphological data are concordant with developmental evidence, confirming that A. willowi is a true case of poecilogony. An improved understanding of the ecological differences between these sister taxa may shed light on the selective pressures that drove the evolution of lecithotrophy in the southern species.
(Received 1 November 2005; accepted 20 September 2006)
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  P. J. Krug Not My "Type": Larval Dispersal Dimorphisms and Bet-Hedging in Opisthobranch Life Histories Biol. Bull., June 1, 2009; 216(3): 355 - 372. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Smolensky, M. R. Romero, and P. J. Krug Evidence for Costs of Mating and Self-Fertilization in a Simultaneous Hermaphrodite With Hypodermic Insemination, the Opisthobranch Alderia willowi Biol. Bull., April 1, 2009; 216(2): 188 - 199. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. J. Krug, M. S. Morley, J. Asif, L. L. Hellyar, and W. M. Blom Molecular confirmation of species status for the rare cephalaspidean Melanochlamys lorrainae (Rudman, 1968), and comparison with its sister species M. cylindrica Cheeseman, 1881 J. Mollus. Stud., August 1, 2008; 74(3): 267 - 276. [Abstract] [Full Text] [PDF]
|
|