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Full-Text Articles in Life Sciences

Marine Invertebrates: Communities At Risk, Jennifer A. Mather Aug 2019

Marine Invertebrates: Communities At Risk, Jennifer A. Mather

Jennifer Mather, PhD

Our definition of the word ‘animal’ centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org) has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical …


What Is In An Octopus's Mind?, Jennifer Mather Aug 2019

What Is In An Octopus's Mind?, Jennifer Mather

Jennifer Mather, PhD

It is difficult to imagine what an animal as different from us as the octopus ‘thinks’, but we can make some progress. In the Umwelt or perceptual world of an octopus, what the lateralized monocular eyes perceive is not color but the plane of polarization of light. Information is processed by a bilateral brain but manipulation is done by a radially symmetrical set of eight arms. Octopuses do not self-monitor by vision. Their skin pattern system, used for excellent camouflage, is open loop. The output of the motor system of the eight arms is organized at several levels — brain, …


Non-Invasive Methods Of Identifying And Tracking Wild Squid, Ruth A. Byrne, James B. Wood, Roland C. Anderson, Ulrike Griebel, Jennifer A. Mather Aug 2019

Non-Invasive Methods Of Identifying And Tracking Wild Squid, Ruth A. Byrne, James B. Wood, Roland C. Anderson, Ulrike Griebel, Jennifer A. Mather

Jennifer Mather, PhD

The ability to identify individual free-living animals in the field is an important method for studying their behavior. Apart from invasive external or internal tags, which may cause injury or abnormal behavior, most cephalopods cannot be tagged, as their skin is too soft and delicate for tag retention. Additionally, cephalopods remove many types of tags. However, body markings have been successfully used as a non invasive method to identify individuals of many different species of animals, including whale sharks, grey whales, seals, and zebras. We developed methods to sex and individually identify Caribbean reef squid, Sepiotheuthis sepioidea. Males showed distinct …


Geographic Variability Of Octopus Insularis Diet: From Oceanic Island To Continental Populations, Tatiana S. Leite, Allan T. Batista, Françoise D. Lima, Jaciana C. Barbosa, Jennifer A. Mather Aug 2019

Geographic Variability Of Octopus Insularis Diet: From Oceanic Island To Continental Populations, Tatiana S. Leite, Allan T. Batista, Françoise D. Lima, Jaciana C. Barbosa, Jennifer A. Mather

Jennifer Mather, PhD

A predator’s choice of prey can be affected by many factors. We evaluated various influences on population dietary composition, individual specialization and size of prey in Octopus insularis populations from 2 continental and 4 insular locations. We expected that habitat diversity would lead to diet heterogeneity. Furthermore, in keeping with MacArthur & Wilson’s (1967) theory of island biogeography, we expected that diet diversity would be lower around islands than on the coast of the mainland. Both predictions were confirmed when prey remains from octopus middens were examined. The 2 continental areas exhibited a richer habitat diversity and a wider variety …


Behaviour Development: A Cephalopod Perspective, Jennifer A. Mather Aug 2019

Behaviour Development: A Cephalopod Perspective, Jennifer A. Mather

Jennifer Mather, PhD

This paper evaluates the development of behaviour from the viewpoint of the intelligent and learningdependent cephalopod mollusks as a contrast to that of mammals. They have a short lifespan, commonly one to two years, and most are semelparous, reproducing only near the end of their lifespan. In the first two months of life, Sepia officinalis cuttlefish show drastic limitation on learning of prey choice and capture, gradually acquiring first short-term and then long-term learning over 60 days. This is paralleled by development of the vertical lobe of the brain which processes visually learned information. In the long nonreproductive adulthood, Octopus …