Marine Biology

, Volume 148, Issue 1, pp 97–108 | Cite as

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

  • P. MartínezEmail author
  • M. Pérez-Losada
  • A. Guerra
  • A. Sanjuan
Research Article


Squids 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.


Parsimony Analysis Enzyme Locus Falkland Island Carboxylic Ester Hydrolase Allozyme Polymorphism 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We are grateful to Dr. Earl Dawe from the Department of Fisheries and Oceans, St. John’s Newfoundland, Canada, to Dr. José Luis Sánchez Lizaso from the University of Alicante, Spain, and to Dr. Scott Herke from the School of Biological Sciences, Loussiana State University, USA, for their helpful sample collections. 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. The experimental procedure complied with current national laws.


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Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • P. Martínez
    • 4
    Email author
  • M. Pérez-Losada
    • 2
  • A. Guerra
    • 3
  • A. Sanjuan
    • 1
  1. 1.Xenética Evolutiva Molecular, Facultade de Ciencias-BioloxíaUniversidade de VigoSpain
  2. 2.Department of Integrative BiologyBrigham Young UniversityUtahUSA
  3. 3.Ecobiomar, Instituto de Investigaciones Marinas (IIM)CSICVigoSpain
  4. 4.Instituto Nacional de ToxicologíaMadridSpain

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