# Observational evidence of egg guarding in wild European squid

## TL;DR

Researchers observed male European squid guarding their eggs, a behavior not previously known in this species or in cephalopods.

## Contribution

This is the first observational evidence of egg guarding behavior in wild European squid and possibly in cephalopods.

## Key findings

- A male European squid was observed guarding eggs for multiple days.
- Both male and female squid were seen interacting with the egg clusters.
- This behavior contradicts the previously assumed reproductive habits of the species.

## Abstract

It is accepted that loliginids, like other squid, deposit their eggs in crevices on the seabed and then abandon them. In this work, we present observational evidence of egg guarding behavior in wild European squid, Loligo vulgaris. While monitoring a squid spawning crevice at night in Spain, a large mass of squid eggs was located and filmed 17 times during 42 days, until hatching. A male and a female of L. vulgaris were filmed in front of the crevice. The same male was filmed guarding the eggs on consecutive days. In the presence of the divers, male and female alternated their approaches to the crevice repeatedly touching and flushing the egg clusters. This guarding behavior differs from the reproductive habits assumed for the European squid and could represent the first evidence of egg guarding by a male in cephalopods.

In this work, we present observational evidence of egg guarding behavior in wild European squid, Loligo vulgaris. Our finding is unexpected because this behavior differs from the reproductive habits assumed for this species. This behavior could represent the first evidence of egg care by a male in cephalopods.