First record of Polyprion oxygeneios (Perciformes: Polyprionidae) for the southwest Atlantic Ocean and a northernmost range extension.

Copyright © 2004 The Fisheries Society of the British Isles.The hapuka Polyprion oxygeneios (Schneider & Foster) (Fig. 1) is an important deep-water commercial fish species, caught mainly off Australia, New Zealand, Juan Fernandez Archipelago off Chile, the Tristan da Cunha Group of the South Atlantic (Sepúlveda & Pequeño, 1986; May & Maxwell, 1986; Paulin et al., 1989; Paxton et al., 1989; Andrew et al., 1995) and incidentally caught off Chilean Patagonia (Nakamura et al., 1986). The distribution of P. oxygeneios is exclusively southern circum-global, intemperate-cold waters from 28_ to 43_ S (Paxton et al., 1989). Polyprion oxygeneios (Polyprionidae; Nelson, 1994) is mainly a demersal species with a depth range of 50–450 m, occurring over ‘rough’ ground from the central shelf to the upper slope (Paxton et al., 1989). It reaches 150 cm total length (LT) and may weigh up to 100 kg, its juveniles being found near the surface, probably associated with drifting material in a way similar to that recorded for Polyprion americanus (Bloch & Schneider) (Paxton et al., 1989; Saldanha, 1995). This paper reports the first record of P. oxygeneios from the south-west Atlantic

Chirocentrodon Bleekerianus (teleostei: Clupeiformes: Pristigasteridae), A Small Predaceous Herring With Folded And Distinctively Oriented Prey In Stomach.

Predaceous fish-eating species of the order Clupeiformes have a large mouth with well-developed teeth, and reach the greatest sizes within their families (up to 90 cm). We found that the pristigasterid Chirocentrodon bleekerianus, a small clupeiform (about 10 cm) from the tropical SW Atlantic, is able to prey on proportionally large clupeoid fishes and caridean shrimps. Fish preys are folded in the stomach of this herring, their heads and tails pointing toward the predator's head. This distinctive orientation of fish prey is also recorded for some small to medium-sized, fish-eating species of the tropical freshwater order Characiformes with canine-like teeth similar to those found in C. bleekerianus.64116516

Conspicuous male coloration impairs survival against avian predators in Aegean wall lizards, Podarcis erhardii.

This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/ece3.1650Animal coloration is strikingly diverse in nature. Within-species color variation can arise through local adaptation for camouflage, sexual dimorphism and conspicuous sexual signals, which often have conflicting effects on survival. Here, we tested whether color variation between two island populations of Aegean wall lizards (Podarcis erhardii) is due to sexual dimorphism and differential survival of individuals varying in appearance. On both islands, we measured attack rates by wild avian predators on clay models matching the coloration of real male and female P. erhardii from each island population, modeled to avian predator vision. Avian predator attack rates differed among model treatments, although only on one island. Male-colored models, which were more conspicuous against their experimental backgrounds to avian predators, were accordingly detected and attacked more frequently by birds than less conspicuous female-colored models. This suggests that female coloration has evolved primarily under selection for camouflage, whereas sexually competing males exhibit costly conspicuous coloration. Unexpectedly, there was no difference in avian attack frequency between local and non-local model types. This may have arisen if the models did not resemble lizard coloration with sufficient precision, or if real lizards behaviorally choose backgrounds that improve camouflage. Overall, these results show that sexually dimorphic coloration can affect the risk of predator attacks, indicating that color variation within a species can be caused by interactions between natural and sexual selection. However, more work is needed to determine how these findings depend on the island environment that each population inhabits.This work was supported by a Biotechnology and Biological Sciences Research Council studentship, Magdalene College, Cambridge and the British Herpetological Society (K.L.A.M), and a Biotechnology and Biological Sciences Research Council and David Philips Research Fellowship (grant number BB/G022887/1) to M.S

Trophic relationships of the spinner dolphin at fernando de noronha archipelago, SW Atlantic

We present an overview of predator-prey and other trophic relationships of spinner dolphins (Stenella longirostris) around Fernando de Noronha Archipelago, off northeastern Brazil, with use of original data and a brief review of data published elsewhere. Records were made while snorkelling among the dolphins in daytime. Individual fish pursuit and coordinated school herding were the two hunting tactics recorded. Three small prey types (oceanic squids, fishes, and prawns) were recovered from vomits collected in situ and from stomachs of two stranded dolphins. In their turn, spinners were preyed on by the cookiecutter sharks (Dalatiidae) as evidenced by round and crater-like wounds and circular scars. Additionally, the dolphins were preyed on by large sharks (Lamnidae, Carcharhinidae), as evidenced by crescent-shaped wounds and scars. Unidentified fishes bit fin pieces, as evidenced by variably-sit aped marks. On the other hand, dolphins' particulate faeces, vomits and live roundworms were eaten by plankton-feeding fishes. Thus, the trophic role of the spinner dolphins of Fernando de Noronha may be summarised as that of : 1) a predator of small oceanic squids, fishes, and prawns; 2) a prey for the small, piece-eating cookiecutter sharks and other unidentified fishes; 3) a prey for large sharks able to kill a dolphin; and 4) a particulate food supplier for plankton-eating fishes.71350551

Estudos sobre a biologia de algas agarófitas. I - recolonização, brotamento e fenologia em populações naturais de Pterocladia capillacea (Rhodophyta-Gelidiaceae)

Experiências e observações realizadas com populações de Pterocladia capillacea do litoral norte do Estado de S. Paulo (Ubatuba) no período de 1968-71 permitiram concluir que: esta espécie ocorre durante o ano todo e que seus indivíduos podem ser considerados como perenes; a reprodução vegetativa através de brotamento das porções basais é bastante eficiente e a regeneração de ramos cortados faz-se rapidamente através da diferenciação de uma célula apical