Bobtail and bottletail squids are small marine invertebrates that are easy to collect, reproduce quickly, and can be raised together in large numbers in laboratories, making them useful model animals for research. They’re cephalopods -- related to true squid, octopus, and cuttlefish, which are renowned for their intelligence and complex behaviors, but of which scientists still know little about. Now, in a new study, published in Communications Biology, researchers have used genetic techniques to show that bobtail squid and bottletail squid share a relatively recent common ancestor and that major biogeographic events might have shaped the evolution of the many different species.

 

‘With 68 recognized species, bobtail squid are a very diverse family and split into three subfamilies. This study found that one of these subfamilies is further split into two geographic lineages.’ explained one of the lead authors, Dr. Gustavo Sanchez, researcher at Hiroshima University and former Visiting Research Student in the Okinawa Institute of Science and Technology Graduate University’s (OIST) Molecular Genetics Unit. ‘In 2019, as part of my previous research at OIST, we described a new species of bobtail squid, which highlights both the diversity present and that many unknowns remain.’ Bobtail and bottletail squids make up the order Sepiolida. They’re small, normally between 1 and 8 cm, and live in a range of marine habitats around the globe, from shallow coastal waters to the open ocean.