Announcing a Special Issue on Elasmobranch Behaviour!

When I discovered sharks in the turquoise Tahitian lagoons, I was fascinated by their complex and clearly intelligent responses in different situations. Based on what I saw myself, I figured they were more intelligent than dogs. But later, when I got an internet connection, I was shocked to learn that science had not noticed!

By then the community I had watched for years was being slaughtered for shark fin soup, so I wrote down the story of my beloved thoughtful sharks in my first book, The Shark Sessions.

Since then I have been trying to publish my findings scientifically, which has been a real challenge for an isolated wildlife artist. However, two years ago, an editor of the journal Behaviour was taken with my writing and invited me to organize a Special Issue on my favourite subject: Elasmobranch behaviour and cognition. It was a real learning experience for me and I was lucky that shark Ethologist Professor A. Pete Klimley offered to help. Not only did his advice serve as a valuable guide in a variety of ways, but his writings have wonderfully enhanced the issue. 

Anyway, I am thrilled, today, to be able to tell you that this Special Issue has finally been published! It is organized into three main themes—Historical Articles,Behaviour, and Cognition—each contributing to a deeperunderstanding of elasmobranchs’ lives and challenging prevailingmisconceptions.

Historical Articles

The issue opens with a groundbreaking review by Guest Editor A.Peter Klimley et al.: a comprehensive ethogram for chimaeras, sharks,and rays. Ethograms are essential for describing animal actions intheir natural habitats and this work was done to aid researchers tocharacterize future sightings as well as to standardize terminologyfor future research. Klimley is an ethologist in the line of NikolaasTinbergen, Konrad Lorenz, and Arthur A. Myrberg Jr., his formerprofessor, who worked for several years with Lorenz in Europe.Klimley carries their legacy forward by creating an ethogram for theentire group of chondrichthyan fishes, and challenging the notion ofsharks as simple feeding machines.

Two historical studies, also by Klimley, follow. The first divesinto the social interactions of hammerhead sharks, revealing acomplex world of social competition and mating behaviours. Femalescalloped hammerheads, for instance, engage in a Cork Screw displayto establish dominance, while males use Torso Thrust to compete formating opportunities. Klimley's study on white sharks unveilsagonistic displays and ritualized behaviours, challenging traditionalstereotypes of sharks as mindless predators.

 

It is followed by a critical commentary by myself, which questions the validity of the study that claimed tohave found dominance-subordination hierarchies in the smooth dogfish.It thus challenges prevailing notions about shark social dynamics.

“The Mistaken Identity Hypothesis for shark bites on humansis an anthropomorphic fallacy” by Eric Emile Germain CluaPh.D., DVM, delves into the reasons behind the widely acceptedhypothesis that sharks mistake swimmers for prey items. Clua proposesa “Natural Exploration Hypothesis,” suggesting thatobserved shark behaviour, including bites on humans, is a response tothe sharks’ natural tendency to strike moving objects at thesurface, rather than a case of mistaken identity.

Behaviour

The Behaviour section is introduced by my own ethogramfor Blacktip Reef Sharks, which describes 35context-specific behaviour sequences. It not only highlights theflexibility in the behaviour of these sharks but also reveals their largeindividual differences. The behavioural repertoire offers intriguingclues as to the complexity of the sharks' cognitive functions.

 

The study is, however, disrupted by the arrival of the shark finindustry, which underlines the devastating impact on sharkpopulations of this largely criminal trade.

“Insight into manta ray behaviour using animal-borneCrittercams” by Nicole Pelletier et al. sheds light on thebehaviour of manta rays in their natural habitats. The study revealsthe importance of social behaviour for these filter-feedingelasmobranchs, with the reef manta ray exhibiting more pronouncedsocial interactions than the giant oceanic manta ray. The studydocuments new inter-specific interactions between these two speciesas well as courtship events.

The article “Could convulsive body shuddering of a whiteshark near a shark cage be an element of a threat display?” by Pete Klimley and Mauricio Hoyos-Padilla challenges commonstereotypes by examining the agonistic displays of a male white sharknear a shark cage. The study emphasizes that even these formidablemarine predators display ordinary animal behaviours in response toperceived threats, debunking the sensationalized portrayals inpopular media.

Cognition

The Cognition section challenges the historical dismissal ofelasmobranch mental capacities. Vera Schluessel et al.’s paper,“When the penny drops: sharks outsmart cichlids in serialreversal learning” sets the tone by testing two species—eightcichlids and seven bamboo sharks—in a reversal learning task. Theresults showcase the sharks’ capacity for learning and behaviouralflexibility, challenging the perception of elasmobranchs asinstinct-driven creatures.

“Examining individual behavioural variation in wild adultbull sharks (Carcharhinus leucas) suggests divergent personalities”by Thomas Matthieu Vignaud et al., takes an ethological approach toanalysing boldness-shyness and aggressiveness-placidity in adult bullsharks. The study not only characterizes individual sharkpersonalities but also quantifies the differences in behaviour overtime, emphasizing the variation among individuals.

The article “Long-lasting memory of a free-ranging topmarine predator, the Bull shark Carcharhinus leucas” byClémentine J. M. Séguigne et al. explores the memory capabilitiesof sharks. Given their long lifespans, sharks are expected to havegood long-term memories, and this study provides evidence supportingthis hypothesis. The sharks quickly resumed their attendance whenfeedings resumed following interruption of shark feedings due to theCOVID-19 pandemic.

The Special Issue concludes on a note of mystery with “Sharkevacuation from Mo’orea Island in 2002” by Ila FrancePorcher. The article recounts a unique event where all Blacktip Reefsharks and likely other species left their lagoon and ocean rangesfor two weeks, thus evading human view without any apparentexplanation. The mystery underscores the gaps in our understanding ofelasmobranchs' lives and behaviours.

In summary, this Special Issue not only unveils the behaviouralcomplexity of elasmobranchs but challenges prevailing stereotypes,emphasizing the need for their conservation. The revelations in thiscollection are poised to inspire further studies and advocate forrobust measures to try to  safeguard these ancient underwaterinhabitants from the current intensive ongoing exploitation.

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