Fish venoms are often poorly studied, in part due to the difficulty in obtaining, extracting, and storing them. In this study, we characterize the cardiovascular and neurotoxic effects of the venoms from the following six species of fish: the cartilaginous stingrays Neotrygon kuhlii and Himantura toshi, and the bony fish Platycephalus fucus, Girella tricuspidata, Mugil cephalus, and Dentex tumi...

Throughout the larval development of a highly euryhaline crab, Neohelice (= Chasmagnathus) granulata, we studied effects of reduced salinities (15 and 25‰ vs. seawater control at 32‰) on larval dry mass (W ) and biochemical composition (total lipid and protein). In the early zoeal stages (I, II), reduced salinity caused delayed moulting, while W and biochemical composition at ecdysis remained u...

Mixed-species grouping is a widespread phenomenon found in arachnids, fish, birds and mammals (Morse 1977; Hodge & Uetz 1992; Bshary & Noë 1997; Herzing & Johnson 1997). Three main reasons have been postulated as to why such heterospecific groups are formed: (1) to improve foraging efficiency, (2) to reduce predation and (3) by chance encounters (Waser 1984; Sakai & Kohda 1995; Noë & Bshary 199...

Gillnets are a widely used fishing gear in Kenya’s artisanal fisheries, yet their mesh sizes inadequately monitored or regulated. This study evaluated the impacts of gillnets seven stretched-mesh sizes, through comparative analysis species-related metrics and catch per unit effort (CPUE), to inform small-scale fisheries regulations. Data were collected from June 2014 May 2015. Three mesh-size g...

Stingrays are an important part of the biomass of the fishes in shallow coastal ecosystems, particularly in inter-reefal areas. In these habitats, they are considered keystone species – modifying physical and biological habitats through their foraging and predation. Here, we quantify the effects of bioturbation by rays on sand flats of Ningaloo Reef lagoon in Western Australia. We measured the ...

Habitat selection decisions by consumers has the potential to shape ecosystems. Understanding the factors that influence habitat selection is therefore critical to understanding ecosystem function. This is especially true of mesoconsumers because they provide the link between upper and lower tropic levels. We examined the factors influencing microhabitat selection of marine mesoconsumers - juve...

Six species of Acanthobothrium, 4 described as new, are reported in stingrays from southern Ecuador. Acanthobothrium atahualpai n. sp. in Gymnura afuerae most closely resembles Acanthobothrium fogeli and Acanthobothrium parviuncinatum by having bothridial hooks with recurved prongs and short handles. It differs from A. fogeli by having bothridial hooks 163-195 microns vs. 78-114 microns long an...

We compared levels of the major organic osmolytes in the muscle of elasmobranchs, including the methylamines trimethylamine oxide (TMAO), betaine and sarcosine as well as the beta-amino acids taurine and beta-alanine, and the activities of enzymes of methylamine synthesis (betaine and TMAO) in species with a wide range of urea contents. Four marine, a euryhaline in freshwater (Dasyatis sabina),...