Paralarval development, abundance, and distribution of Pterygioteuthis hoylei (Cephalopoda: Oegopsida: Pyroteuthidae) in the Gulf of California, México

Abstract

The morphology and ecology of paralarvae (PL) through to the juvenile stages are unknown in most cephalopod species in spite of their importance as indicators of biodiversity, of adult spawning grounds, and as key basis for fisheries management programs. We describe, for the first time, the morphological development of Pterygioteuthis hoylei (Pfeffer 1912) and used cytochrome C oxidase for genetic identification of specimens, linking PL with both juveniles and adults. Pterygioteuthis hoylei represents the most abundant species of squid in oblique plankton collections in the Gulf of California, México. PL were collected in plankton tows made in the Gulf of California from 2004 to 2007. Almost all morphological features followed an increasing size/count trend. Most specimens were collected during March–May, accounting for 71.8% of total cephalopod paralarval abundance, and in November (13.5%). Size, abundance and distribution analyses indicate a high abundance of recently hatched PL (1.1–2.0 mm mantle length) off Bahía Concepción to Bahía de La Paz in these months along with the highest abundance of juveniles and adults in the same area. These results indicate that reproductive activity of P. hoylei takes place in the southern Gulf of California in late winter to early spring, and in November, representing an important spawning and hatching area for this species.

Keywords:

• squid
• hatching area
• spawning season
• morphology
• size abundance
• DNA

Acknowledgements

This contribution is part of the requirements of the postgraduate program of the Universidad de Guadalajara, México. This work was done under research programs supported by Consejo Nacional de Ciencia y Tecnología (CONACyT) and Comisión de Operación y Fomento de Actividades Académicas of Instituto Politécnico Nacional (COFAA-IPN). RDS was supported by a CONACyT post-graduate, and COFAA and EDI grants. The authors thank Jaime Gómez-Gutiérrez (CICIMAR-IPN, México), Erick Zettler (Sea Education Association, Woods Hole Laboratory, Massachusetts, USA), and Secretaría de Marina, Armada de México, for access to GOLCA, S-, and CGC samples and oceanographic data, respectively. Peter Gaede prepared final inked figures at the Santa Barbara Museum of Natural History from original drawings of specimens by RDS. Comments by referees Mark Norman and C.C. Lu were especially helpful in revising the manuscript.