Gp. Manchenko et al., High level of genetic divergence between sympatric color morphs of the littoral sea anemone Anthopleura orientalis (Anthozoa : Actiniaria), BIOCH SYST, 28(8), 2000, pp. 737-750
Using enzyme electrophoresis and nematocyst analysis, the sympatrically occ
urring "light" and "dark" color morphs of the sea anemone Anthopleura orien
talis from the Sea of Japan were shown to be two valid species. The "light"
morph was identified as A. orientalis (Averintsev, 1967 Issledovaniya faun
y morel. Vyp. 5 (13). Nanka, Leningrad, pp. 62-77). while the "dark" morph
was designated as Anthopleura sp. The analysis of 21 isozyme loci revealed
high value of Nei's genetic distance (D = 1.284) between the two species, w
hich are indistinguishable in their external morphology. The mean values of
observed and expected heterozygosities for A. orientalis and Anthopleura s
p. are high (H-o=0.252 +/- 0.061, H-e = 0.250 +/- 0.061 and H-o = 0.327 +/-
0.052, H-e = 0.351 +/- 0.054, respectively). The species differ significan
tly in the size of spirocysts and nematocysts, among which the atrichs from
acrorhagi and the basitrichs from actinopharynx contribute most to the obs
erved difference.. Strong qualitative difference is revealed between distri
butions of nematocysts in mesenteric filaments of the two sea anemone speci
es studied. The possible conspecificity of Anthopleura sp. with Anthopleura
artemisia (Dana, 1848) is discussed and the conclusion made that these an
two separate species. (C) 2000 Elsevier Science Ltd. All rights reserved.