A preliminary investigation of the use of subcutaneous tagging in Caribbean reef squid Sepioteuthis sepioidea (Cephalopoda: Loliginidae)

This paper describes a new method developed to directly measure size and temperature specific growth rates of individual wild squid. Our tag and recapture method is complimentary to previously employed statolith aging methods but provides finer scale detail. The Caribbean reef squid, Sepioteuthis sepioidea, is an ideal model organism for field work on squid life-history as they live in shallow coastal areas and are accessible. These squid were tagged and monitored for tag retention and growth rates over a period of 56 days in the laboratory and 27 days in the field. A total of 103 squid were tagged, 10 in the laboratory and 93 in the field. Visible Implant Elastomer (VIE) tags and Visible Implant Alphanumeric (VI Alpha) tags were used during this experiment. None of the VI Alpha tags were retained in laboratory animals, but VIE tags remained visible for the duration of the laboratory study and were used in all field studies. The 10 recaptured squid weighed from 19.1 to 122.9 g with an average and standard deviation recapture weight of 56.9 ±35.5 g, compared to their original weights of 48.0 ±30.5 g. In the field, these squid had instantaneous growth rates of 1.19–3.10 with an average growth rate of 1.93 ± 0.71 at temperatures ranging from 19.5 to 23.7 °C.