A Novel Resource Polymorphism in Fish, Driven by Differential Bottom Environments: An Example from an Ancient Lake in Japan

Divergent natural selection rooted in differential resource use can generate and maintain intraspecific eco-morphological divergence (i.e., resource polymorphism), ultimately leading to population splitting and speciation. Differing bottom environments create lake habitats with different benthos communities, which may cause selection in benthivorous fishes. Here, we document the nature of eco-morphological and genetic divergence among local populations of the Japanese gudgeon Sarcocheilichthys (Cyprinidae), which inhabits contrasting habitats in the littoral zones (rocky vs. pebbly habitats) in Lake Biwa, a representative ancient lake in East Asia. Eco-morphological analyses revealed that Sarcocheilichthys variegatus microoculus from rocky and pebbly zones differed in morphology and diet, and that populations from rocky environments had longer heads and deeper bodies, which are expected to be advantageous for capturing cryptic and/or attached prey in structurally complex, rocky habitats. Sarcocheilichthys biwaensis, a rock-dwelling specialist, exhibited similar morphologies to the sympatric congener, S. v. microoculus, except for body/fin coloration. Genetic analyses based on mitochondrial and nuclear microsatellite DNA data revealed no clear genetic differentiation among local populations within/between the gudgeon species. Although the morphogenetic factors that contribute to morphological divergence remain unclear, our results suggest that the gudgeon populations in Lake Biwa show a state of resource polymorphism associated with differences in the bottom environment. This is a novel example of resource polymorphism in fish within an Asian ancient lake, emphasizing the importance and generality of feeding adaptation as an evolutionary mechanism that generates morphological diversification

Molecular characterization of MHC class IIB genes of sympatric Neotropical cichlids

Ministerio de Economía y Competitividad del Gobierno de España, Programa de Formación de Personal Investigador FPI BES-2011-047645 to MJH, Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia Proyecto CGL 2010-16103 to MB. This project was further enabled through two German Science Foundation grants to CE (DFG, EI841/4-1 and EI841/6-1) both part of the SPP 1399 priority programme on “host-parasite interactions”

A New Hemichordate, Saccoglossus bromophenolosus (Hemichordata, Enteropneusta, Harrimaniidae), From North america

Volume: 107Start Page: 383End Page: 39

Eocuma Petrescui, A New Species Of Bodotriid Cumacean (Crustacea : Peracarida) From Malaysia

Volume: 116Start Page: 978End Page: 98

Do Observer Effects Matter? A Comment on Langenburg, Bochet, and Ford

We identify methodological problems in Langenburg et al. (2014), which undermine its conclusions about the size of the observer effect problem and the importance of sequential unmasking as a solution. The scoring method of Langenburg et al. (2014) appears to be subjective. The classification of cases is not congruent with the three keys to observer effects in forensic science: the analyst\u27s state of expectation, the analyst\u27s state of desire, and the degree of ambiguity in the evidence being examined. Nor does the paper adequately support its claim, “[I]t has been asserted that the high context/high interaction cases are essentially where there is the most danger of bias.” While the paper tends to minimize concern over observer effects, the evidence in it seems to support the view that fingerprint analysts look to contextual information to help them make decisions