First genetic validation and diagnosis of the short-finned squid species of the genus Illex (Cephalopoda: Ommastrephidae)

12 páginas, 3 figuras, 5 tablas.-- The original publication is available at www.springerlink.comSquids of the genus Illex are representative of the family Ommastrephidae and account for 65% of the world’s cephalopod captures. Illex is formed by four taxa distributed throughout the Atlantic Ocean (I. argentinus, I. coindetii, I. illecebrosus and I. oxygonius), whose identification and phylogenetic relationships based on morphological characters remain controversial. Thirty-seven enzyme-coding loci were analysed in 230 individuals from seven populations of Illex and ten specimens of Todaropsis eblanae, which were used as the outgroup. Two to four enzyme loci (ALPDH*, IDHP- 1*, MEP* and SOD*) were diagnostic among Illex species depending on the species-pair comparison. Individuals morphologically identified as I. oxygonius were also found genetically distinct, which proves the taxonomic validity of this species. No significant intraspecific genetic heterogeneity was detected within Illex argentinus, I. coindetii and I. illecebrosus (Mean GST= 0.011, 0.003, 0.017, respectively). I. illecebrosus and I. oxygonius were shown as sister species with a close relationship to I. argentinus, whereas I. coindetii formed a different lineage.This research was supported by the projects 64102C028 (Universidade de Vigo, Spain) and REN2000-1193 MAR (Ministerio de Ciencia y Tecnología, Spain) to A.S. Portions of this paper fulfilled Ph.D. requirements for P.M., who received a scholarship from University of Vigo.Peer reviewe