CARIBBEAN REEF OCTOPUS EGG DEVELOPMENT AND HATCH IN SITU: AN ANNOTATED PHOTO-TECHNICAL REPORT

The Caribbean Reef Octopus Octopus briareus typically has a 15-18 month life span. As its common name implies, it can be found on reefs of the Caribbean and is fairly common to the waters of the lower Florida Keys, US. The animal reaches sexual maturity at around four months and does well in public aquariums.  Although much is known about its sexual reproduction in captivity, in situ observation of the animal's brooding habits are not well documented.   

Florida Keys Community College in Key West, FL, maintains a 40-foot deep dive lagoon at the rear of its campus that is used for training by marine science classes, dive teams, rescue operations, and government agencies from across the country. Since Fall 2013, female Caribbean Reef Octopuses have been observed brooding eggs in small recessed holes within the lagoon.

A primary objective of this study was to determine the seasonal, temperature-dependent variation in time mothers were in brood.  A secondary objective was to photo-document development of the young within eggs over time.  

The first mother observed hung her eggs on October 12, 2013, which hatched November 20, for an incubation period of 40 days. A second mother hung her eggs on January 19, 2014, which hatched April 3, for an incubation period of 75 days. The average water temperature was much colder from January to April, than it was from October to November. On both of these first occasions, the mothers were observed in situ before laying eggs, and the eggs were observed with them subsequently. Photographs were taken underwater of egg development approximately every 3 days until hatch via SCUBA.

Although the recessed habitats were monitored frequently in years following, no other octopuses were observed brooding in the lagoon again until Fall 2018. Two female octopuses with eggs were first observed in two different locations in the lagoon on September 26, 2018 and October 3, 2018. The eggs of the former hatched on October 27, 2018 and the eggs of the latter began hatching on November 3, 2018. Photographs and video were taken underwater of egg development approximately every 3 days until hatch via SCUBA. In addition, images and video of juveniles hatching were captured from the latter mother's brood.

To our knowledge, this is the first time development and hatch of O. briareus has been tracked and documented in situ. The unique dive-training facilities of Florida Keys Community College enable repeated, long-term observation for the continued study of the brooding and early life history of this species.