Sphyrna Zygaena Research Articles

Artisanal Shark Fishery at "Tres Marias" Islands and Isabel Island in the Central Mexican Pacific

There is a lack of basic biological information on the shark species caught in the region around the Tres Marias Islands and Isabel Island in the Central Mexican Pacific. Intensive monitoring was undertaken from October 1995 to March 1996 of shark landings by the artisanal fleet at La Cruz de Huanacaxtle, Nayarit, that fished south of Tres Marias Islands and, from November 2000 to February 2001, of landings by another fleet that fished around Isabel Island and close to the Tres Marias. Smooth hammerhead Sphyrna zygaena (35%), silky shark Carcharhinus falciformis (27%) and blue shark Prionace glauca (25%) were the most important species of 2 004 sharks observed at La Cruz de Huanacaxtle. At Isabel Island, the most important species of 7 464 sharks sampled were S. lewini (49%) and Pacific sharpnose shark Rhizoprionodon longurio (45%). This paper describes the shark species caught at these islands, the catch per unit effort of the principal species throughout the fishing season, their length frequency distributions and percent mature, and gear selectivity issues.

Taxonomic reports of Homeacanthoidea (Eucestoda: Trypanorhyncha) in Lamnid and Sphyrnid elasmobranchs collected off the coast of Santa Catarina, Brazil

Elasmobranch specimens of lamnid and sphyrnid captured in 1999 in the State of Santa Catarina, Brazil, were parasitized with homeacanthoid trypanorhynch cestodes: Isurus oxyrinchus Rafinesque, 1810 with Nybelinia lingualis (Cuvier, 1817) Dollfus, 1929; Sphyrna zygaena (Linnaeus, 1758) with Heteronybelinia rougetcampanae (Dollfus, 1960) Palm, 1999. New details of internal morphology and/or scolex and/or proglottid surface ultrastructure are given. Adults of N. lingualis are reported for the first time in the Brazilian coast.

First Observations of Feeding on Thresher <I>(Alopias vulpinus)</I> and Hammerhead <I>(Sphyrna zygaena)</I> Sharks by Killer Whales <I>(Orcinus orca)</I> Specialising on Elasmobranch Prey

Killer whale (Orcinus orca) predation on elasmobranchs (sharks and rays) is not often reported. In New Zealand waters, killer whales captured and ate thresher (Alopias vulpinus) and smooth-hammerhead (Sphyrna zygaena) sharks. Both species were not reported previously as prey of killer whales. These observations help support the idea that elasmobranchs are a main prey type for New Zealand killer whales; ten species of elasmobranchs are now recorded as prey for this population.

Characteristics of structure, composition, mass spectra, and iron release from the ferritin of shark liver ( Sphyrna zygaena)

The ferritin consists of a protein shell constructed of 24 subunits and an iron core. The liver ferritin of Sphyrna zygaena (SZLF) purified by column chromatography is a protein composed of eight ferritins containing varying iron numbers ranging from 400±20 Fe 3+/SZLF to 1890±20 Fe 3+/SZLF within the protein shell. Nature SZLF (SZLF N) consisting of holoSZLF and SZLF with unsaturated iron (SZLF UI) to have been purified with polyacrylamide gel electrophoresis (PAGE) exhibited five ferritin bands with different pI values ranging from 4.0 to 7.0 in the gel slab of isoelectric focusing (IEF). HoloSZLF purified by PAGE (SZLF E) not only had 1890±20 Fe 3+/SZLF E but also showed an identical size of iron core observed by transmission electron microscopy (TEM). Molecular weight of ∼21 kDa for SZLF E subunit was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Four peaks of molecular ions at mass/charge ( m/ z) ratios of 10611.07, 21066.52, 41993.16, and 63555.64 that come from the SZLF E were determined by matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS), which were identified as molecular ions of the ferritin subunit (M +) and its polymers, namely, [M] 2+, [M] +, [2M] +, and [3M] +, respectively. Both SZLF E and a crude extract from shark liver of S. zygaena showed similar kinetic characteristics of complete iron release with biphasic behavior. In addition, a combined technique of visible spectrometry and column chromatography was used for studying ratio of phosphate to Fe 3+ within the SZLF E core. Interestingly, this ratio maintained invariable even after the iron release, which differed from that of other mammal ferritins.

A revision of F. R. Irvine's Ghanaian marine fishes in the collections of The Natural History Museum, London

Some 180 species of marine fish were reported from Ghana in F. R. Irvine's The Fishes and Fisheries of the Gold Coast, an important milestone in West African ichthyology published in 1947. Although the book has been a major source of records for subsequent workers, the underpinning collections have been largely ignored. Two hundred and ninety-two specimens from 139 species collected by Irvine and colleagues were located within The Natural History Museum collections and are reported here with notes on their zoogeography. These were re-identified in the light of the intervening half century of research and have allowed us to examine the basis for most of Irvine's records by matching Irvine's collection numbers (referred to in his book) to BMNH registration numbers. In addition to registered material some 26 jars of unregistered material containing 46 specimens were discovered. About 20% of the species were found to have been misidentified. Six of the marine species collected by Irvine were described by J. R. Norman as new species between 1930 and 1935. These remain valid as: Rhinobatos albomaculatus Norman, 1930; Rhinobatos irvinei Norman, 1931; Serranus accraensis (Norman, 1931); Spicara nigricauda (Norman, 1931); Branchiostegus semifasciatus (Norman, 1931) and Pontinus accraensis Norman, 1935. A further nine species collected by Irvine were at the time unknown to science and have since been described by others as new species. Of particular interest is a specimen of Panturichthys isognathus Poll, 1953 which appears to be only the second adult specimen reported. Most of the 39 species for which material could not be located represented uncontentious records. However, there were eight species listed by Irvine, for which no voucher specimens could be located, which are unlikely to occur off Ghana, and a further two species (Carcharodon carcharias and Alopias vulpinus) for which Irvine's records cannot be considered a basis for a Ghana record. Five species (Conger conger, Umbrina cirrosa, Scorpaena scrofa, Chaetodon striatus and Liza ramada) are considered as doubtful records based on misidentifications. Three other species (Dentex macrophthalmus, Sphyrna zygaena and S. tudes) appear unlikely records for Ghana but cannot be totally dismissed. Inter alia this study demonstrates the critical importance of voucher specimens in museum collections to support biodiversity research.

Prevalência e intensidade de infecção de cestóides Trypanorhyncha de elasmobrânquios nos estados do Paraná e Santa Catarina, Brasil

Twenty-nine specimes (32.2%) of elasmobranch fishes, out of 90 captured in the south coast of Brazil in the States of Parana and Santa Catarina, represented by six families, seven genera and nine species, were parasitized with cestodes of the order Trypanorhyncha: Heptranchias perlo and Squalus sp. parasitized with Progrillotia dollfusi; Isurus oxyrinchus with Nybelinia lingualis and Gymnorhynchus isuri; Prionace glauca with Tentacularia coryphaenae, Hepatoxylon trichiuri, Molicola horridus, Floriceps saccatus and Callitetrarhynchus gracilis; Carcharhinus signatus with Heteronybelinia yamagutii, H. nipponica and P. dollfusi; C. longimanus and C. obscurus with T. coryphaenae; Sphyrna zygaena with Heteronybelinia rougetcampanae and Callitetrarhynchus speciosus; Dipturus trachydermus with Mixonybelinia beveridgei. Prevalences and intensities of infection are presented as well as the analysis of the hosts sex-related parasitism, in single or concomitant infections. Data are discussed and compared with previous available reports on these hosts, mainly those referring to the species I. oxyrinchus, P. glauca and C. longimanus

Cephalopods in the diets of four shark species ( Galeocerdo cuvier, Sphyrna lewini, S. zygaena and S. mokarran ) from KwaZulu-Natal, South Africa

The cephalopod components of the diets of four species of shark, tiger Galeocerdo cuvier, smooth hammerhead Sphyrna zygaena, scalloped hammerhead S. lewini and great hammerhead S. mokarran, were examined to reveal patterns of prey choice. Although these sharks were caught in the inshore gillnets used in KwaZulu-Natal to protect bathers from shark attack, prey included neritic and oceanic taxa that were pelagic, epibenthic or benthic. In all, 3 387 lower beaks were found in the stomach contents. A total of 15 families was identified from 117 tiger sharks with cephalopod lower beaks in their stomachs. Sepiidae, Octopodidae and Ancistrocheiridae were most numerous and dominated in terms of mass. Of the 422 scalloped hammerheads with lower beaks in their stomachs, Octopodidae, Octopoteuthidae and Ancistrocheiridae were the most dominant of the 12 families identified. The cephalopod prey items of 258 smooth hammerheads were dominated by Loliginidae. Sepiidae and Ancistrocheiridae were also major components of ...

A comparative study on liver ornithine carbamoyl transferase from a marine mammal Stenella and an elasmobranch Sphyrna zygaena

1. 1. Ornithine carbamoyl transferases from liver of the dolphin Stenella and the shark Sphyrna zygaena were purified to homogenity and compared for some kinetic and structural properties. 2. 2. The two enzymes showed a specific activity of 211 and 115 respectively. 3. 3. With respect to molecular weight, trimeric subunit structure and K m values, they were alike and similar to enzymes from other species. 4. 4. Both enzymes were thermolable, but they were protected from thermal inactivation in a different way by ornithine and phosphate. 5. 5. The two enzymes focused, respectively, at pH 8.6 and between pH 6.4 and 8.0, the former value being appreciably higher than those of enzymes from other species.

Occurrence and feeding of three shark species,Carcharhinus brachyurus, C. obscurusandSphyrna zygaena, on the Eastern Cape coast of South Africa

The shark species Carcharhinus brachyurus, C. obscurus and Sphyrna zygaena, which attain more than 2 m when adult, occur in coastal waters of the Southern Cape as juveniles. They use these coastal waters as nursery areas and their relative abundance there varies through the year, possibly because of seasonally varying oceanographic conditions. Adult C. brachyurus occur in the same geographic area but usually deeper, although there is some overlap in juvenile and adult depth ranges. Adult C. obscurus prefer the warmer subtropical and tropical waters north of the study area. Adult S. zygaena are found over deep reefs at the edge of the continental shelf. There was considerable dietary overlap between the three species, the prey of all three being dominated by small schooling fish, such as pilchard, and squid. For the three species, animals of total length >2 m took larger prey, such as elasmobranchs, with greater frequency, although they continued to prey on squid and schooling fish. It is postulated that the nursery areas are in the study area because of the abundance of food there, and that avoidance of cannibalism would be enhanced by the use of such nurseries.

Parasitic copepods of Carcharhinidae and Sphyridae (Elasmobranchia) from the Atlantic Ocean

Seventy-four sharks of the families Carcharhinidae and Sphyridae, mainly from the central Atlantic Ocean, were examined. Fourteen species of Copepoda were found on them. Prionace glauca and Sphyrna zygaena are new hosts for the copepod Pandarus floridanus. Kroyeria carchariaeglauci is reported from the nasal cavities of Prionace glauca for the first time.

High hemoglobin mixed disulfide content in hemolysates from stressed shark

1. 1. Hemolystate from heavily stressed smooth hammerhead shark, Sphyrna zygaena, shows three electrophoretic components, SZ I, SZ II and SZ III, whose relative concentrations are 36.4 ± 6.8, 36.4 ± 5.0 and 20.8 ± 5.7%, respectively. After reduction with DTE only SZ I remained. 2. 2. SZ I reacted with glutathione disulfide reconstitute SZ II and SZ III. 3. 3. Non-reduced, DTE-reduced, and denatured hemoglobin were found to have 2.0 ± 0.4, 3.7 ± 0.6, and 9.4 ± 0.7-SH groups, respectively. 4. 4. Erythrocyte non-protein—SH (NPSH), including glutathione present as mixed disulfide with SZ II and SZ III, is 1.7 NPSH/Hb.

Biological observations on sharks caught by sport fisherman of New South Wales

Between 1979 and 1982, 523 sharks representing four families and 13 species were examined from sport fishing catches off New South Wales. Additional catch data were available from records of the Sydney Game Fishing Club extending from 1953 to 1979. The species composition of sharks caught changes through the year, probably as a result of seasonal variations in water temperature. Prionace glauca and Isurus oxyrinchus are most abundant in the catches during the cooler months from May to November. Galeocerdo cuvieri, Carcharhinus brevipinna, C. longimanus, C. falciformis, C. limbatus and Sphyrna lewini are taken principally during the warmer months from December to April. The sex ratio of P. glauca and Sphyrna zygaena changes through the year due to a seasonal influx of gravid females. At least six of the species examined give birth off New South Wales and, apart from C. falciformis, all of these appear to have restricted breeding seasons. P. glauca and S. zygaena feed mainly on cephalopods and to a lesser extent on fish, I. Oxyrinchus principally on fish, and G. cuvieri mostly on fish, birds, unidentified mammals and cephalopods.

Observations on some Tasmanian fishes: Part XXIII

CARCHARHINIDAE. Carcharhinus greyi greyi, second recorded specimen from Tasmania (first recorded as C. brachyurus); head in plan, mouth parabolic curves, orthogonal polynomials fitted; girth of head an exponential function of length from snout tip; notes on dentition, coloration; key to Tasmanian carcharhinids. SPHYRNIDAE. Sphyrna zygaena, second recorded Tasmanian example, female, compared with first, male; logarithmic lengths to seven morphological landmarks yield a linear graph when plotted on logarithms of seven natural numbers (similar formulations in other sharks). SYNGNATHIDAE. Syngnathus phillipi, study of two samples (meristic and morphometric data, variation within and between samples, supposed sexual dimorphism, pouch, coloration, depth range): Syngnathus caretta (apparently known only from type-specimens) reported from Tasmania; current knowledge of species extended: IchthyocaIlzpus runa noted as a Tasmanian species: Syngnathus poecilolaemus, metrical data. LAMPRIDAE. Lampris regius, new and old local records. SCORPIDAE. Scorpis aequipinnis, morphometry and coloration in a juvenile sample; comparison with adult material, yielding data on regional relative growth. LEPTOSCOPIDAE. Crapatalus arenarius, new subspecies described and figured. TRIPTERYGIIDAE. General review of Tasmanian representatives, with key; Tripterygium clarkei (later placed in Gillias and Norfolkia) here referred to Helcogramma: specimen noted in R.M. Johnston's memoranda, identified as T. clarkei by Whitley, now described as a new species: Gillias macleayana, new material, table of dimensions: two new species of Forsterygion (New Zealand genus new to Australia) described and figured: Brachynectes fasciatus retained in that genus; size classes. ECHENEIDAE. Remora remora, observations on two Tasmanian examples (host, Luth); outline of disc fitted with second degree polynomial; lengths of transverse ridges of disc an exponential function of their serial numbers; unusual white markings in one specimen. SYNANCEJIDAE. Glyptauchen insidiator mirandus, habits; first detailed account of the subspecies; length-number patterns of spines and rays; taxonomic status discussed.

Studies on a New Trypanorhynchan Larva, Callotetrarhynchus sp., parasitic on Cultured Yellowtail—IX

In order to know the final host ofCallotetrarhynchussp. observation was made of the contents of digestive tracts of 110 sharks of 10 different species collected in the Bungo Channel and adjacent seas.Scolecis of the cestoda were first found out in the valvular intestine of a hammerhead shark, Sphyrna zygaena, caught on April 29, 1970. The scolecis, however, occurred only at the terminal section of the spiral valve and half of them were moving into the colon without fixingwith tentacles to the spiral valve, which suggested that this shark had no aptitude for a final host of the cestoda.Adults and scolecis settled in the valvular intestine were detected in a specimen of Scoliodon walbeemi of about 2.2m in body length caught on October 31, 1970. The adults and scolecis numbered 62 and 21, respectively. Thus this species was thought to be one of the final hosts.Besides 593 adults and 74 scolecis were obtained from the valvular intestine of an unidentified shark caught on September 23, 1971.

Noteworthy elasmobranch records from Oman

Records of 11 elasmobranch species previously unreported from, or uncommon in, Omani waters are presented. Records new to Oman include Carcharhinus altimus, C. leiodon, Centrophorus isodon, Ctenacis fehlmanni, Himantura fai, Mobula eregoodootenke and Sphyrna zygaena, whereas noteworthy records of uncommon species include Himantura imbricata, Paragaleus randalii, Rhinobatos salalah and Taeniura meyeni – some of which are confirmed from the Gulf of Oman for the first time. These records bring to 57, the number of elasmobranch species confirmed in Omani waters.

各種魚類の体表面粘質物および軟骨中のsialic acid

Five kinds of sialic acid have so far been described1)2). In the present paper, the authors tried to identify and determine the sialic acids occurring in the external mucous substance from a sting ray, Dasyatis akajei, and an eel, Anguilla japonica, and in the cartilage of a shark, Carcharhinus gangeticus, a hammerhead, Sphyrna zygaena, and a sting ray. The isolation procedure of sialic acids was the same as that described in the previous paper3)4). Each material was hydrolyzed with 0.03N H2S04 at 80°C for 1 hr. The sialic acid liberated was retained on Dowex-1 (HCOO-), and then eluted with 0.3N HCOOH. The eluate was evaporated to dryness in vacuo at a temperature not exceeding 30°C. The residue was dissolved in water-methanol, and sialic acid was crystallized from the solution by adding ethyl ether. The identification of sialic acids was performed by paper chromatography developed with three kinds of solvent (Table 1). The content of sialic acid in each material was determined by SVENNERHOLM's resorcinol reaction8). Among the sialic acids only N-acetylneuraminic acid was identified in all the samples tested, and the unidentified substances positive to the “direct EHRLICH's reaction” were found, besides N-acetylneuraminic acid, in both the external mucous substance of an eel and the cartilage of a hammerhead. The content of sialic acid in each material tested was shown in Table 2.

ウナギ体表面粘質物とシュモクザメ軟骨とから得られた sialic acid 類似物質について

It has been reported by the authors1) that the sialic acid-like substances (positive substance to “direct EHRLICH reaction”) were obtained from both the external mucous substance of an eel, Anguilla japonica, and the cartilage of a hammerhead, Sphyrna zygaena. The present work was undertaken to make clear the chemical properties of these two substances. From the absorption spectra of those substances by some colour reactions specific for sialic acid, the ultraviolet absorption spectra of those and the acid- or alkali-treated derivatives of N-acetylneuraminic acid, and from the paper chromatograms of the degradation products of the sialic acid-like substances, it was suggested that the two substances are the degradation products of the sialic acid by the mild acid hydrolysis during the extraction from the materials. It seems most likely that the sialic acid-like substance of an eel is a heavily degraded product and that of a hammerhead a slightly degraded one.

A synopsis of the hammerhead sharks (Sphyrna), with description of a new species

While working upon material obtained recently in the Gulf of Aden I found it necessary to examine the collection of Hammerhead Sharks in the British Museum (Nat. Hist.). The results of this study were somewhat surprising and have necessitated the publication of this paper. During my work in the field I distinguished three species which I named Sphyrna zygaena, S. mokarran and S. tudes, in accordance with the previously accepted definitions of these forms, but it now appears that not one of these names was correctly applied. The position can best be made clear by discussing briefly each of these in turn.

肝油の高周波による採取

The liver oil of hammer head shark [Sphyrna zygaena (L.)] has been extracted by the radio heaters. The operating frequencies were 13 megacycles in the case of Test 1, 2 (Fig. 1) and 78, 55 megacycles in the case of Test 3, 4 (Fig. 2). The vitamin A content of the dropped out oil was lower than that of the remained oil in the cooked liver. Its data are shown in the following tables (Table 1, 2, 3 and 4).

A Comparison of Atlantic and Pacific Specimens of the Hammer-Head Shark, Sphyrna zygaena

A Comparison of Atlantic and Pacific Specimens of the Hammer-Head Shark, Sphyrna zygaena