Taxonomic status of two South American sympatric squat lobsters, Munida gregaria and Munida subrugosa (Crustacea: Decapoda: Galatheidae), challenged by DNA sequence information

PATRICIA PEREZBARROS,; MARIA EUGENIA D´AMATO; NOELIA V. GUZMÁN; GUSTAVO ALEJANDRO LOVRICH

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2008 vol. 94 p. 421 - 424

0024-4066

We investigated the taxonomic status of two sympatric morphospecies of squat lobsters from southern SouthAmerica (Beagle Channel, Strait of Magellan, and Burdwood Bank), Munida gregaria and Munida subrugosa, byDNA sequence analysis of three mitochondrial (mt)DNA gene fragments [416 bp of 16S rDNA(165), 566 bp ofcytochrome c oxidase subunit I(COI) and 418 bp of NADH dehydrogenase subunit 1 (ND1)]; and the nuclear rDNAinternal transcribed spacer (ITS) 1 (883–952 bp). We obtained a total of 79 sequences from 32 individuals. The 16Ssequences of all M. gregaria and M. subrugosa were invariant and identical, whereas COI and ND1 showed 12 and15 variable sites, respectively. These polymorphisms were shared between morphospecies. Interspecific Tamura–Nei distances for COI and ND1 sequences were 0.0024 and 0.0032, respectively, and were not significantly differentfrom intraspecific distances (Kruskal–Wallis tests: P = 0.58 and P = 0.69, for COI and ND1, respectively). Similarto the results obtained from the mtDNA sequences, no relationship was found between the ITS1 maximumparsimony tree topology and the morphologic classification of specimens in M. gregaria and M. subrugosa. Weconclude that M. gregaria and M. subrugosa from southern South America may either represent a case of adimorphic species, or a case of incomplete lineage sorting. The fact that these two morphospecies did not show fixeddifferences over a total of 1947 bp analysed reinforces the hypothesis of a single dimorphic species. © 2008 TheLinnean Society of London, Biological Journal of the Linnean Society, 2008, 94, 421–434.ADDITIONAL KEYWORDS: 16S – COI – ITS1 – genetic variation – ND1 – speciation.