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Seattle, WA, United States

Scheel D.,Alaska Pacific University | Anderson R.,Seattle Aquarium
American Malacological Bulletin | Year: 2012

We examined variation in dietary specialization of Enteroctopus dofleini (Wülker, 1910), the giant Pacific octopus, from Puget Sound to the Aleutian Islands, as represented in midden remains. Dietary specialization was measured from midden contents as: species richness (R) and Cardona's niche breadth (regional indices), and proportional similarity of a midden to the regional sample (an individual index). We found an influence of items per midden and prey species maximum size on these indices. In Puget Sound, middens and common prey species were large, richness, R = 21 species, and individuals specialized more often than in other areas, typically on large prey species. In Saanich Inlet, British Columbia, middens were smaller, R = 9 species, and the large crab Cancer productus was common in nearly all middens, such that the population specialized rather than the individual. In Prince William Sound, Alaska, middens contained fewer individuals of smaller prey species, R = 52 species, and diet was generalized at both the population and the individual levels. Cardona's niche breadth ranged from . 11 to . 14 except in the Aleutian Islands, Alaska where it was higher (.30). Most individual E. dofleini were generalists, and dietary species richness was very high (R = 69 species overall). Specialists within a generalist population were common only where middens and dominant prey were both large. Source


The broadnose sevengill shark, Notorynchus cepedianus, a common coastal species in the eastern North Pacific, was sampled during routine capture and tagging operations conducted from 2005-2012. One hundred and thirty three biopsy samples were taken during these research operations in Willapa Bay, Washington and in San Francisco Bay, California. Genotypic data from seven polymorphic microsatellites (derived from the related sixgill shark, Hexanchus griseus) were used to describe N. cepedianus genetic diversity, population structure and relatedness. Diversity within N. cepedianus was found to be low to moderate with an average observed heterozygosity of 0.41, expected heterozygosity of 0.53, and an average of 5.1 alleles per microsatellite locus. There was no evidence of a recent population bottleneck based on genetic data. Analyses of genetic differences between the two sampled estuaries suggest two distinct populations with some genetic mixing of sharks sampled during 2005-2006. Relatedness within sampled populations was high, with percent relatedness among sharks caught in the same area indicating 42.30% first-order relative relationships (full or half siblings). Estuary-specific familial relationships suggest that management of N. cepedianus on the U.S. West Coast should incorporate stock-specific management goals to conserve this ecologically important predator. © 2015 Larson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source


Anderson R.C.,Seattle Aquarium | Shimek R.L.,PO Box 4
American Malacological Bulletin | Year: 2014

There are several references to octopuses eating birds but few give details of the encounters. Here we document the details of seven instances (six Enteroctopus dofleini (Wülker, 1910) and one Octopus cf. insularis Leite and Haimovici, 2008) of octopuses attacking, capturing or eating birds, including glaucous-winged gulls (Larus glaucescens), a pigeon guillemot (Cepphus columba), a double-crested cormorant (Phalacrocorax auritus), a western grebe (Aechmophorus occidentalis) a brown noddy (Anous stolidus) and a bald eagle (Haliaeetus leucocephalus). © 2014, BioOne. All rights reserved. Source


Sea star wasting disease, the cause of which remains uncertain, has baffled scientists since it first appeared in the summer of 2013. Some species of the affected sea stars act lethargic or have arms that are abnormally curled upward; others abruptly change color. In either case, they soon develop skin lesions through which their internal organs may eventually fall out. In the end, their limbs detach, and they die. What makes this outbreak so alarming is that it is occurring from Mexico to Alaska and involves more than 20 species, says Littman. Millions have died. Previous incidents of wasting disease were restricted to a very small geographic range and affected only a few species. A significant loss of stars could have a dangerous domino effect. "You don't think of them as being particularly fast," says Littman, "but sea stars are important keystone predators in the tide pools." His summer studies investigated whether sea stars with the wasting disease could be identified before they showed outward signs of it. While early detection won't benefit sea stars in the wild, it would help aquatic veterinarians care for captive ones, which are getting sick just as much as their wild counterparts. Early indicators of the disease, Littman theorized, could be found in density scans of the sea creatures. His research followed up on the findings of a Monterey Bay Aquarium veterinarian who had seen some decreased density in the bodies of sea stars with the wasting syndrome. Littman's work was supported by the International Association for Aquatic Animal Medicine and the national AQUAVET program based at Cornell University. Felicia Nutter, V93, a research assistant professor of infectious disease and global health at Cummings School, hooked the third-year veterinary student up with veterinarians Lesanna Lahner of the Seattle Aquarium and Marty Haulena of the Vancouver Aquarium. Under their mentorship, Littman compared images of ailing and healthy sea stars in hopes of finding telltale density variations. He was interested in the tiny bones, called ossicles, that run throughout the bodies of sea stars. These vary in shape and size and form the skeletal network that supports a star's body. One of the biggest challenges Littman faced was how to use technology to get images of the ossicles. In human medicine, doctors use dual X-ray absorptiometry to measure bones' mineral density and diagnose conditions like osteoporosis. But the machines that do these scans are very expensive. Besides, he says, "I would have also needed to be able to compare the results to a range of 'normals,' which didn't exist" for sea stars. Maurice Solano, an assistant professor of diagnostic imaging at Cummings School, gave him tips on how to use software to come up with a range of normal densities for healthy sea stars, Those densities could then be compared with the densities of sea stars with wasting disease. Littman had hoped that X-ray, which is inexpensive and widely available, would help him detect the disease, but the invertebrates' unusual anatomy foiled that plan. "You put a star on a table and shoot a beam down to get one flat picture, but because [all the ossicles] overlap, and not all stars are of uniform thickness, X-ray turned out to be impractical for determining their densities," he says. CT scans did the job. Because a CT scanner takes hundreds of cross-sectional pictures, Littman was able to assess sea star ossicles in several different planes and even in 3-D. "We weren't able to determine where a lesion was going to appear on the skin of a sick sea star," he says, "but we were able to get the overall density of a sea star and determine whether it was above or below the 'normal' determined from CT scans of healthy stars. Our preliminary data showed that the ossicles of healthy stars have much higher density." Now back on campus, Littman expects to be first author, with Lahner and Haulena, on a forthcoming paper about how to perform an X-ray on a sea star to help diagnose other conditions. He says he hopes to continue working with sea stars and other marine animals. "The ocean covers 70 percent of the earth, and we know less about it than we do about space," says Littman. "Invertebrates, fish, marine mammals, sea turtles—that's where my passion lives."


Larson S.,Seattle Aquarium | Belting T.,Seattle Aquarium | Rifenbury K.,Sea For Life | Boutelle S.M.,Wildlife Contraception Center
Zoo Biology | Year: 2013

The sea otter (Enhydra lutris) is a popular exhibit animal in many zoos and aquariums worldwide. Captive sea otters from these populations are owned by the United States Fish and Wildlife Service (USFWS). The USFWS has requested that these sea otters be prevented from breeding in order to save captive space for wild rescued animals. Sea otters are often housed in mixed sex groups, therefore a chemical contraceptive method or surgical removal of gonads must be used to prevent potential pregnancy. The contraceptive, Suprelorin® or deslorelin, has been used in many different species to effectively suppress reproduction but duration of effect may vary not only between species but also individuals. Here, we report the effects of one to several consecutive deslorelin implants on gonadal reproductive hormones found in fecal samples from six captive sea otters (two males and four females) compared to two control otters (one male and one female) housed at three zoological institutions. We documented the longitudinal hormone signatures of many stages of the contraceptive cycle including pretreatment (PT), stimulatory phase (S), effective contraception (EC), and hormone reversal (HR) that was characterized by a return to normal hormone levels. Deslorelin was found to be an effective contraceptive in sea otters and was found to be reversible documented by a live birth following treatment, however the duration of suppression in females was much longer than expected with a 6-month and a 1-year implant lasting between 3 and 4 years in females. © 2012 Wiley Periodicals, Inc. Source

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