Species Identification And Phylogeny Of Phycinae Hakes And Related Gadoid Fishes

The term hake refers to a number of species belonging to multiple families of fish in the suborder Gadoidei and includes two main groups: Phycinae hakes (family Gadidae) and Merluccius spp. hakes (family Merlucciidae). The use of the common name hake for this diverse group of fish prompts questions such as: how are these species related and how can they be differentiated? Chapter one details the development of the Rapid Gadoid Identification Assay (RaGIA) for molecular identification of 11 gadoid fishes (including six hakes) using Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP). RaGIA was used for species identification of fillets of hake, pollock and haddock sold in southern Maine markets. Testing found that market labeling was accurate; however, there were inconsistences in the labels provided by the fish distributors (from whom the markets obtained their fillets). Chapter two explores the development of a phylogeny, based on a mitochondrial DNA gene and a nuclear encoded gene, which includes members of the families Gadidae and Merlucciidae. The resulting phylogeny was used for morphological character mapping and investigation of trait evolution in this group. Consistent with previous studies, the analysis resolved the families Gadidae, as well as several subfamilies, and Merlucciidae with strong support. The putative Lotinae subfamily clade was not resolved in this analysis and suggests that further study is needed to investigate the monophyly of this group. The three dorsal fins and two anal fins morphological states as well as the life history characteristic of the absence of an egg oil globule were all found to be characteristic of the Gadinae, the most derived clade of the Gadoidei

What the Hake?! Fish Forensics in Maine Markets

Mislabeling of seafood is a widespread issue, not just locally but worldwide. Researchers at the University of New England have developed a molecular method for identifying six species of hake and an additional five groundfish species common to the Gulf of Maine

A rapid phenotype change in the pathogen Perkinsus marinus was associated with a historically significant marine disease emergence in the eastern oyster

The protozoan parasite Perkinsus marinus, which causes dermo disease in Crassostrea virginica, is one of the most ecologically important and economically destructive marine pathogens. The rapid and persistent intensification of dermo in the USA in the 1980s has long been enigmatic. Attributed originally to the effects of multi-year drought, climatic factors fail to fully explain the geographic extent of dermo’s intensification or the persistence of its intensified activity. Here we show that emergence of a unique, hypervirulent P. marinus phenotype was associated with the increase in prevalence and intensity of this disease and associated mortality. Retrospective histopathology of 8355 archival oysters from 1960 to 2018 spanning Chesapeake Bay, South Carolina, and New Jersey revealed that a new parasite phenotype emerged between 1983 and 1990, concurrent with major historical dermo disease outbreaks. Phenotypic changes included a shortening of the parasite’s life cycle and a tropism shift from deeper connective tissues to digestive epithelia. The changes are likely adaptive with regard to the reduced oyster abundance and longevity faced by P. marinus after rapid establishment of exotic pathogen Haplosporidium nelsoni in 1959. Our findings, we hypothesize, illustrate a novel ecosystem response to a marine parasite invasion: an increase in virulence in a native parasite

Assimilating Dokdo: The Islets in Korean Everyday Life

Sovereignty over the Tokto Islets is heatedly contested between South Korea and Japan. The Korean government and citizenry have responded to this dispute by inserting the islets into their national collective memory in multifarious ways in an attempt to strengthen their nation’s claim to Tokto. The islets are included in the material culture and public memory of the nation in ways that make them part of everyday life for millions of Koreans. Korea’s claim to Tokto is currently taught in schools, presented in museums, found in popular songs, and exploited by businesses for profit. The deeper Tokto becomes entrenched in Korean society, the less likely a compromise can be reached with Japan over the islets