Early morphological studies regarding the evolutionary history of elasmobranchs suggested sharks and batoids (skates and rays) were respectively monophyletic. More modern morphological cladistic studies, however, have tended to suggest that batoids are derived sharks, closely related to sawsharks and angelsharks, a phylogenetic arrangement known as the Hypnosqualea hypothesis. Very few molecula...

To investigate the physical mechanism of the electric sense, we present an initial electrical characterization of the glycoprotein gel that fills the electrosensitive organs of marine elasmobranchs (sharks, skates, and rays). We have collected samples of this gel, postmortem, from three shark species, and removed the majority of dissolved salts in one sample via dialysis. Here we present the re...

The PFRP was host to “Tagging and Tracking Marine Fish with Electronic Devices,” a major international symposium held at the East-West Center in Honolulu from February 7–11, 2000. More than 100 scientists and electronics manufacturers from a dozen countries assembled to share their findings and discuss the state-of-the-art in this rapidly developing field. Results from all of earth’s oceans wer...

BACKGROUND Modern selachians and their supposed sister group (hybodont sharks) have a long and successful evolutionary history. Yet, although selachian remains are considered relatively common in the fossil record in comparison with other marine vertebrates, little is known about the quality of their fossil record. Similarly, only a few works based on specific time intervals have attempted to i...

Antibiotics are a relatively common disturbance to the normal microbiota of humans and agricultural animals, sometimes resulting in severe side effects such as antibiotic-associated enterocolitis. Gambusia affinis was used as a vertebrate model for effects of a broad-spectrum antibiotic, rifampicin, on the skin and gut mucosal microbiomes. The fish were exposed to the antibiotic in the water co...

Surimi refers to concentrated myofibrial protein extracted from fish flesh by washing process. Surimi powder, is normally prepared in a dried form, and potentially useful as a raw material for preparation of seafood products. Surimi powder offers many advantages in industrial application, such as easy handling, low distribution cost, and physically convenient for addition to dry mixtures. In or...

BACKGROUND The relationships of cartilaginous fishes are discussed in the light of well preserved three-dimensional Paleozoic specimens. There is no consensus to date on the interrelationship of Paleozoic chondrichthyans, although three main phylogenetic hypotheses exist in the current literature: 1. the Paleozoic shark-like chondrichthyans, such as the Symmoriiformes, are grouped along with th...

Sexually dimorphic head shape is common in vertebrates from teleosts to mammals. Herein we document that cephalic sexual dimorphism is also found in the cartilaginous fishes (Chondrichthyes). Male bonnethead sharks develop a prominent bulge along the anterior margin of the cephalofoil at the onset of sexual maturity. This contrasts with the uniformly rounded anterior margin of adult females and...

Please cite this article in press as: Raihani, N dx.doi.org/10.1016/j.anbehav.2012.06.023 Inequity aversion (IA), a willingness to incur temporary costs to prevent unequal outcomes, is common in humans and thought to be beneficial in the context of cooperative relationships with nonkin, since it might allow individuals to regulate contributions to cooperative activities. Attempts to address whe...