Fishes of the deep demersal habitat at Ngazidja (Grand Comoro) Island, Western Indian Ocean

Underwater observations of the coelacanth, Latimeria chalumnae Smith, 1939, from a research submersible provided opportunities to study the deep demersal fish fauna at the Comoro Islands. The demersal habitat in depths of 150–400 m at the volcanic island of Ngazidja is low in fish diversity and biomass, compared with the shallow-water coral reef habitat of Ngazidja or the deep demersal habitats of other localities in the Indo-Pacific region. The resident deep demersal fish fauna at Ngazidja is dominated by the coelacanth, an ancient predator that is specially adapted for this low-energy environment. Other large fish predators are scarce in this environment, because of the heavy fishing pressure from local fishermen. Eighty-nine fish taxa (including 65 recognizable species) were recorded from videotapes, photographs, visual observations, fishermen’s catches and ancillary attempts to sample the fish fauna with baited fish traps, gill nets, and hook and line. Although no coelacanth feeding events were seen, seven fish species are known from coelacanth stomach contents, and 64 other fish species in this habitat are considered potential prey of this dominant predator

Fishes of the deep demersal habitat at Ngazidja (Grand Comoro) Island, Western Indian Ocean

Underwater observations of the coelacanth, Latimeria chalumnae</I> Smith, 1939, from a research submersible provided opportunities to study the deep demersal fish fauna at the Comoro Islands. The demersal habitat in depths of 150-400 m at the volcanic island of Ngazidja is low in fish diversity and biomass, compared with the shallow-water coral reef habitat of Ngazidja or the deep demersal habitats of other localities in the Indo-Pacific region. The resident deep demersal fish fauna at Ngazidja is dominated by the coelacanth, an ancient predator that is specially adapted for this low-energy environment. Other large fish predators are scarce in this environment, because of the heavy fishing pressure from local fishermen. Eighty-nine fish taxa (including 65 recognizable species) were recorded from videotapes, photographs, visual observations, fishermen's catches and ancillary attempts to sample the fish fauna with baited fish traps, gill nets, and hook and line. Although no coelacanth feeding events were seen, seven fish species are known from coelacanth stomach contents, and 64 other fish species in this habitat are considered potential prey of this dominant predator

Interactions of fishes with particular reference to coelacanths in the canyons at Sodwana Bay and the St. Lucia Protected Area of South Africa

The deep demersal fish fauna at depths of 100–400min canyons off the St Lucia Marine Protected Area along the north coast of KwaZulu-Natal is compared with similar fish communities at the Comoro Islands and in the Indo-Pacific region. Fifty-four fish species were seen or photographed from the submersible Jago or by the discovery team of scuba divers in the coelacanth, Latimeria chalumnae, habitat of the canyons off Sodwana Bay. An additional 94 fish species known from depths of 100–200 m along the coast of northern KwaZulu-Natal are likely to occur in the canyon habitat. The fish fauna of the Sodwana canyons shares at least 18 species with the deep demersal fish community off tropical coral reefs of the Indo-Pacific region. Thirty-seven of the Sodwana canyon fishes are also known from the coelacanth habitat in the Comoros

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

The African hind's (Cephalopholis taeniops, serranidae) use of artificial reefs off Sal Island (Cape Verde): a preliminary study based on acoustic telemetry

The African hind Cephalopholis taeniops (Valenciennes, 1828) is one of the most important commercial demersal species caught in the Cape Verde archipelago. The species is closely associated with hard substrate and is one of the main attractions for SCUBA divers. In January 2006 a former Soviet fishing vessel - the Kwarcit - was sunk off Santa Maria Bay (Sal Island). Young C. taeniops are commonly observed in this artificial reef (AR). In order to investigate the species' use of the AR, 4 specimens were captured and surgically implanted underwater with Vemco brand acoustic transmitters. The fish were monitored daily with an active telemetry receiver for one week after release. Simultaneously, an array of 3 passive VR2 / VR2W receivers was set for 63 days, registering data that allowed an analysis of spatial, daily and short term temporal activity patterns. The results showed site fidelity to the AR, with no migrations to the nearby natural reef. The method used allowed to register a consistent higher activity during daytime and a preference for the area opposite the dominant current

Crystallographic Evidence of Drastic Conformational Changes in the Active Site of a Flavin-Dependent

The soil actinomycete Kutzneria sp. 744 produces a class of highly decorated hexadepsipeptides, which represent a new chemical scaffold that has both antimicrobial and antifungal properties. These natural products, known as kutznerides, are created via nonribosomal peptide synthesis using various derivatized amino acids. The piperazic acid moiety contained in the kutzneride scaffold, which is vital for its antibiotic activity, has been shown to derive from the hydroxylated product of l-ornithine, l-N5-hydroxyornithine. The production of this hydroxylated species is catalyzed by the action of an FAD- and NAD(P)H-dependent N-hydroxylase known as KtzI. We have been able to structurally characterize KtzI in several states along its catalytic trajectory, and by pairing these snapshots with the biochemical and structural data already available for this enzyme class, we propose a structurally based reaction mechanism that includes novel conformational changes of both the protein backbone and the flavin cofactor. Further, we were able to recapitulate these conformational changes in the protein crystal, displaying their chemical competence. Our series of structures, with corroborating biochemical and spectroscopic data collected by us and others, affords mechanistic insight into this relatively new class of flavin-dependent hydroxylases and adds another layer to the complexity of flavoenzymes.National Center for Research Resources (U.S.) (P41RR012408)National Institute of General Medical Sciences (U.S.) (P41GM103473

Age and growth of the dusky grouper Epinephelus marginatus (Lowe 1834) in an exploited population of the western Mediterranean Sea

Publicado