Inshore spawning grounds of the squid Doryteuthis gahi suggest the consistent use of defoliated kelp Lessonia trabeculata in Central Chilean waters

ABSTRACT

Coastal spawning grounds of the squid Doryteuthis gahi were identified for the first time at three sites in Central Chile during 2014 and 2015. A total of 15 egg masses were collected from between 10 and 15 m depth and brought to the laboratory for evaluating capsular, embryonic and when possible, paralarval characters. Egg capsules from all spawning areas were similar in size (∼25 mm in length) and number of embryos per capsule (∼15). Egg-laying patterns, in addition to field observations, suggest that relatively small D. gahi may be using shallow waters in semi-protected environments to reproduce and spawn. Additionally, the differential use of healthy versus defoliated kelp Lessonia trabeculata suggests that egg-laying females selectively choose substrata that limit mechanical damage to the fragile egg capsules and that also allow for adequate water flow, which could be reduced in a mass of kelp fronds. These findings highlight the opportunistic behaviour of D. gahi which use overgrazed L. trabeculata, a condition that is widespread in areas with high herbivory pressure.

RESPONSIBLE EDITOR:

• Omar Hernando Ávila-Poveda

KEY WORDS:

• Defoliation
• egg-laying
• egg size
• kelp
• Loliginidae
• paralarvae

Acknowledgements

The authors would like to thank Randy Finke and Ricardo Calderón (ECIM) for providing boat assistance at Punta de Tralca. Vladimir Garmendia and Catalina Ruz (SUBELAB) helped during field collections at this study site. Ignacio Borgeaud (Bajomar Ecodive) provided technical assistance at Canelillo and underwater videos for supplementary material. Franco Salas (VALPOSUB) provided support during field collections at Valparaíso. Menko Dijkstra (Van Hall Larenstein University) helped with egg-capsule measurements in the laboratory. The comments of Dr Nicole E. Phillips greatly improved preliminary versions of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the FONDECYT-CONICYT research grants no. 3140416 and no. 1151094 awarded to SC and APM, respectively. Additional support from Iniciativa Científica Milenio (ICM – CCM RC 130004), Fondo de Innovación para la Competitividad, Ministerio de Economía, Fomento y Turismo, Chile, is also appreciated.