Original text and photos by OIST, edited by Emma Buchet.
quote from Dr. Sydney Brenner, molecular geneticist and one of the founders of
the Okinawa Institute of Science and Technology Graduate University (OIST),
highlights the burgeoning scientific interest in cephalopods like cuttlefish,
octopuses, and squid. These creatures are lauded for their complex nervous
systems and intricate behavior – but scientists still know relatively little
researchers in OIST’s Molecular Genetics Unit, in
collaboration with a researcher from Australia, have identified a new species
of bobtail squid inhabiting Okinawa’s waters – dubbed Euprymna brenneri in honor of the late Dr. Brenner, who passed away earlier this year.
The scientists’ findings, published in Communications Biology, highlight
the rich biodiversity in the seas near Okinawa, and may shed light on the
genes, behavior, and development of bobtail squid.
“Our research strives to understand how these animals’ complicated brains work… We’re also compelled to explore why there is such a wide variety of species off the coast of Okinawa.”
said Gustavo Sanchez, currently an Assistant Professor at Hiroshima University, lead author of the study.
and classifying a new species
have unique features from true squid, including their rounded or “bobbed” posteriors,
earning them the nickname “dumpling squid.” In fact, they are actually more
closely related to cuttlefish. Bobtails can be raised in the laboratory, making
them useful as model for studying cephalopod development, genetics, and
behavior. Scientists have also observed advanced behaviors like associative
learning and inherited personality and fitness traits in bobtails.
the present study, the researchers scoured the Ryukyan archipelago for
bobtails, searching in shallow waters. They found three different types of egg
masses and two distinct adult bobtails.
studying the DNA and RNA expression, or transcriptomes, in 42 different
individuals across 10 species, the researchers matched the adults with their
corresponding egg types and identified one of them as Euprymna parva, which
was previously miscategorized as a different genus. One egg mass lacked a
corresponding adult; by DNA it appeared to be distantly related to a different
species found in Australia and East Timor, Euprymna pardalota.
Ryukyuan type of bobtail remained. In addition to sequencing its transcriptome,
the scientists closely analyzed its morphology; Jeff Jolly observed distinctive
patterns of suckers on its arms and tentacles. The researchers enlisted the
help of systematist Dr. Amanda Reid, from the Australian Museum in Sydney, to
carefully look over the species and formally describe them.
their analyses, the scientists confirmed they had found a new species, which
they named Euprymna brenneri. This species is the eleventh known in the Euprymna
genus and will be useful in future
phylogenetic and comparative studies, the researchers said.
“Sydney Brenner was a mentor and a friend. It
is an honor to name this new species after him as a small reminder of his
importance in creating the field of molecular biology, and more broadly his
efforts to foster the development of science in Okinawa, Singapore, and around
the world,” said Daniel Rokhsar, head of the Molecular Genetics Unit at
addition to phylogeny, the scientists are interested in the bobtail squid’s
symbiotic relationship with the Vibrio fischeri bacteria that populate a
pouch-like organ on the squid’s underside. Bobtails conceal themselves under
the sand throughout the day, then emerge at night to hunt. They use the
bacteria, which glow, to help them camouflage and achieve more successful
predation in the dark.
a complicated choreography between the bacteria and squid,” said Dr. Oleg
Simakov, a co-author of the study. “If we can understand this relationship, we
think the bobtail could be a useful model organism for host-microbe
Moving forward, the researchers hope to discover more about the rich diversity of cephalopods off the shores of Okinawa, and to further explore the relationships between different bobtail species.
Original article: Sanchez, G., Jolly, J., Reid, A. et al. New bobtail squid (Sepiolidae: Sepiolinae) from the Ryukyu islands revealed by molecular and morphological analysis. Commun Biol 2, 465 (2019) doi:10.1038/s42003-019-0661-6
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