In the present study, the cestoid Pterobothrium crassicolle Diesing, 1850 (Trypanorhyncha), was observed parasitizing specimens of the violet goby (Gobioides broussonnetii Lacepède, 1800) collected from the estuary of the Paracauarí River on Marajó Island in the north of the Brazilian state of Pará, between January 2009 and December 2010. Tissue samples were analyzed, which led to identificatio...

Abstract Migration barriers being selective for invasive species could protect pristine upstream areas. We designed and tested a prototype protective barrier in vertical slot fish pass. Based on the individuals’ swimming responses to flow field, we assumed this would block ascension of round goby, but allow comparable native (gudgeon bullhead) ascend. The was three steps: description, quantific...

Coral reef lagoons and back reef areas are composed more of sand than hard reef habitat. They support a diverse mix of fishes, including species restricted to sandy habitats and those dependent on both hard and soft substrata. However the resident assemblages associated with sand and the factors affecting their distribution and abundance are poorly understood. Here we examine spatial co-variati...

Marine fish species such as grey wrasse Symphodus cinereus, common sole Solea solea, knout goby Mesogobius batrachocephalus and rusty blenny Parablennius sanguinolentus were studied for their parasitic isopods on the Sinop coast of Black Sea. Two cymothoid (Nerocila bivittata Nerocila orbignyi) identified. was found body surface fins wrasse, sole, goby, N. orbignyi dorsal fin blenny. The preval...

Vertebrates show left-right biases in turning direction, limb usage, predator-escape response and use of sensory organs. In particular, some fishes are known to have lateral biases in predatory behaviors corresponding to their morphological antisymmetry. To reveal the effects of these laterally biased behaviors on predator-prey interaction, we conducted behavioral tests of predatory events betw...

In this study, we investigated the characteristics of CCK-producing cells and mucus-secreting goblet cells with respect to stomach fish and stomachless fish of the Gobiidae in order to provide a basis for understanding the digestive physiology. Hairychin goby (Sagamia geneionema), which is stomachless fish, the numbers of mucus-secreting goblet cells is highest in the posterior intestine portio...

One of the chemical breakdown products of nonylphenol ethoxylates, 4-nonylphenol (4-NP), accumulates in organisms and is of concern as an environmental pollutant due to its endocrine disrupting effects. We measured 4-NP levels in the seawater, sediment, and twelve organisms within the California estuary, Morro Bay, and examined biomagnification of 4-NP using stable isotope abundances (δ(15)N an...

Aggregations of the Ponto-Caspian invasive zebra mussel (Dreissena polymorpha) constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to pre...

island populations of the lake erie watersnake (Nerodia sipedon insularum) have experienced a dramatic environmental change in the form of a new abundant prey species, the round goby (Neogobius melanostomus). effects of this biotic change on watersnake reproductive characteristics were tested by comparing offspring size and the relationship between female size and offspring number before and af...