September 20, 2014

Cuttlefish and Camouflage

Justine and a cuttlefish (Sepia officinalis) in the Aegean Sea near Çeşmealtı, Turkey. Photograph courtesy of Derya Akkaynak Yellin.

 

Coleoid cephalopods (cuttlefish, octopus and squid) cue on visual stimuli in their surroundings and rapidly camouflage themselves via changes in their color, posture, locomotion and, in cuttlefish and octopus, skin texture. Because these animals are prey to a variety of animal groups (teleost and cartilaginous fish, diving birds, marine mammals, other cephalopods), their camouflage behavior must trick diverse visual systems. This ecology makes cephalopods an excellent model for the study of visual perception, both from the perspective of the predators searching for camouflaged prey and from the perspective of cephalopods choosing an appropriate body pattern for effective camouflage in a given visual scene.

Justine Allen is a Brown-MBL PhD student in Roger Hanlon’s lab at the MBL. Justine became interested in adaptive camouflage while an undergraduate at the State University of New York (SUNY), Geneseo. After earning her BS in biology, she worked as an intern, research assistant 1 and research assistant 2 in Roger Hanlon’s lab. Justine joined the Brown-MBL graduate program in the fall of 2009 and moved to Providence to begin her PhD in the neuroscience department.  After passing her comprehensive exams, she returned to Hanlon’s lab to begin her thesis work

As a research assistant, Justine led animal behavior studies that examined the cues that evoke cuttlefish skin papillae, tested whether cuttlefish have a preference for a particular substrate, explored the limits of cuttlefish vision in low light, and studied the visual cues that contribute to cuttlefish postural camouflage. She also contributed to studies of Mottle patterns and masquerade in cuttlefish camouflage and collaborated with researchers at the National Tsing Hua University in Taiwan and the U.S. Military Academy at West Point. This group used a hyperspectral imager to examine the degree of color match between cuttlefish skin and surrounding substrate from the perspective of fish predators. More recently, Justine was part of teams of researchers who examined cuttlefish color match in the field and elucidated the mechanism of the ring flashing behavior of blue-ringed octopus.

Justine is an avid field biologist and earned her American Academy of Underwater Sciences scientific diving certification in 2008.  She has traveled with Roger Hanlon and others to study Nassau groupers and slender filefish in Little Cayman, octopuses in Florida and Puerto Rico, and cuttlefish in Turkey.

Justine’s PhD thesis will include a study of the functional morphology of cuttlefish papillae using a variety of histological techniques. She is presently working in collaboration with engineers at the University of Pittsburgh to understand the biomechanics of this component of cuttlefish and octopus camouflage.

Justine is fortunate and grateful for support from a National Defense Science and Engineering Graduate Fellowship and a National Science Foundation Graduate Research Fellowship Program award.