Speciation in the coral-boring bivalve Lithophaga purpurea: evidence from ecological, biochemical and SEM analysis

Abstract

The bonng mytil~d L~thophaga purpurea densely inhabits the scleractinian corals Cyphastrea c h a l c~d~c u m (Forskal 1775) and Montlpora erythraea Marenzeler, 1907 In the Gulf of Ellat, Red Sea Profound differences in reproductive seasons postlarval shell morphology and isozyme polymorphism exlst between the bivalve populatlons inhabihng the 2 coral specles w h~c h share the same reef environments Two distlnct reproductive seasons were identified in the blvalves L purpurea inhabiting A4 erythraea reproduce in summer while those In C chalcjd~cum reproduce in late fall or early winter SEM observations revealed distlnct postlarval shell morphologies of bivalves inhabiting the 2 coral hosts Postlarvae from C c h a l c~d c u m are chalactenzed by tooth-like structures on their dissoconch, as opposed to the smooth dissoconch surface of postlarvae from M erythraea In addition, there is a significant difference ( p < 0 001) In prodissoconch height between the 2 bivalve populations Results obtained from isozyme electrophores~s showed d~stinct patterns of aminopeptidase (LAP) and esterase polymorphism, indicating genehc differences between the 2 populahons These data strongly support the hypothesis that L purpurea inhabiting the 2 coral hosts are indeed 2 d~stlnct specles Species specificity between corals and their symbionts may therefore be more predominant than prev~ously beheved

The gill morphology of the date mussel Lithophaga lithophaga (Bivalvia: Mytilidae)

“…Although a number of previous studies have addressed the life history and ecological features of the members of the genus Lithophaga (Valli et al, 1986;Scott, 1988;Brickner et al, 1993;Sinis, 1994-1995;ElMenif et al, 2007;Devescovi, 2009), including limited descriptions of the general anatomy of the genus (Turner and Boss, 1962;Simone and Goncalves, 2006), very little has been published on its ctenidial structure (Turner and Boss, 1962). Well-documented observations are available on other genera of Mytilidae: Mytilus, Mytella, and Perna (Aiello and Sleigh, 1972;Domouhtsidou and Dimitriadis, 2000;Gregory and George, 2000;Gregory et al, 2002;David and Fontanetti, 2005;David et al, 2008).…”

Functional phenotypic plasticity of the endolithic mytilidLeiosolenus curtus(Lischke, 1874) (Bivalvia: Mytilidae)

“…Fungiacava generally bores into mushroom corals, and Leiosolenus also bores into hermatypic corals (Goreau et al 1969;Kleemann 1980;Morton 1983Morton , 1990Hoeksema and Kleemann 2002;Kleemann and Hoeksema 2002). Species of Leiosolenus are suggested to differ from each other according to the species of the living corals into which they bore (Mokady et al 1991(Mokady et al , 1992(Mokady et al , 1994Brickner et al 1993). The species diversity of Leiosolenus is highest among endolithic mytilids (Morton 1983(Morton , 1990Kleemann 1990).…”