Date of Degree

9-2019

Document Type

Dissertation

Degree Name

Ph.D.

Program

Biology

Advisor

Jennifer Basil

Committee Members

Frank Grasso

John Chamberlain

John Waldman

Jean Boal

Subject Categories

Behavior and Ethology | Ecology and Evolutionary Biology

Keywords

behavior, chambered nautilus, social behavior, reproductive behavior, oval squid

Abstract

Cephalopods are a highly specialized group of molluscs that show a wide range of behavioral patterns. Chambered nautilus (Nautilus pompilius) and oval squid (Sepioteuthis lessoniana) are two very distinct species of cephalopod that both provide unique insight into cephalopod reproductive and social behavior. In experiments utilizing both species, I aimed to fill in knowledge gaps in a range of reproductive behaviors from fundamental responses to conspecifics, to preferred mating habitat.

In Chapter 1 and 2 I tested individual nautiluses in a Y-maze where recipients were exposed to paired odors of two donor nautiluses. I collected data on both their choice of scent as well as their tentacle extension behavior as they approached a chosen scent. This allowed me to answer questions concerning whether the opposite or same sex scent were more attractive, as well as if there were individuals’ scents within the opposite sex that were most attractive. In Chapter 3 I completed further analysis of the first two chapters and concluded that Nautilus does not show particular preference for the opposite sex or certain individuals when choosing their scents in a Y-maze. However, Nautilus showed differing patterns of tentacle extension in response to the scent of the opposite sex when compared to the same sex. Further, females and males showed dissimilar topography of response. These findings suggest that detection of conspecific scent may not mean choosing that scent. Further, scent choice and potential mate choice may take place under alternate circumstances, if at all. Finally, that tentacle extension response to conspecific scent may provide evidence for social behavior in chambered nautilus.

In Chapter 4 I exposed oval squid to varying habitat types in the laboratory environment and measured the occurrence of two mating behaviors as well as squid location within each habitat. This allowed me to determine the height of the habitat in which squid were most likely to mate (bare, short, or tall) as well as the habitat composition in which they were most likely to mate (seagrass or coral). Results showed that squid choose bare and short habitats and show more variation in mating behavior in the seagrass habitat when compared to coral. Further, habitat choice while mating differed in some measures from habitat choice when not mating. Overall I concluded that oval squid prefer short and bare seagrass habitats for mating, which may indicate where they would mate and spawn in the wild.

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