bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization and cartography of some Mediterranean soft-bottom benthic communities (Ligurian Sea, Italy)
Authors: Somaschini A. , Martini N. , Gravina M. F. , Belluscio A. , Corsi F. , Ardizzone G. D.
Published: October 2008

Soft-bottom benthic communities were studied along the Western coast of the Ligurian Sea with a new approach using both videocamera surveys and collected samples. The preliminary distribution of soft-bottoms and the definition of the limits and status of seagrass beds were carried out in September 1991, using an underwater vehicle provided with a videocamera and towed by a boat. Moreover, 90 benthic samples were collected at 5-40 m depth in order to characterize the macrobenthic soft-bottom communities. Six soft-bottom benthic assemblages and two sea grass biotopes (Cymodocea nodosa and Posidonia oceanica) were revealed by means of underwater images and multivariate analysis (TWINSPAN) on samples collected. The communities inhabiting the infralittoral sandy and coarse sediments corresponded to those previously described in the Mediterranean Sea, whereas a large complex transition between sandy and muddy communities was recognized on circalittoral soft-bottoms. Information obtained with this approach was used to draw a map of the investigated areas at 1:10,000 scale. The employment of the two techniques was cost effective for both time and research effort.
Description of two new species of microcotiloids, monogenean parasites in marine fish from the north eastern cost of Venezuela
Authors: Fuentes Zambrano José Luis
Published: October 2008

Two new species monogenean, found in gills of marine fish from the north easter cost of Venezuela are described: Kannaphalus mochimae found in Acanthurus coeruleus (Acanthuridae) and Allopyragraphorus marinae found in Strongylura marina (Belonidae). K. mochimae differs from K. virilis Unnithan, 1957 in shaped and location of the genitals and number of clamps and testis(K. mochimae posses 69 to 76 and 15 - 20 respectively, while K. virilis has 33 at 46 and more than 100 respectively). On the order hand, K. lateriporis Mamaev, 1988, another related species, has different structure and form of the vagina, asymmetrical clamps and copulatory organ displaying a short styled. K. univaginalis Ramalimgam, 1960 presents only one vaginal pore, while K. mochimae presents two pore. A. marinae differs from the other three described species of genus in: body size, form of the opisthaptor, number of clamps, number and arrangement of testis, and shaped and arrangement of the ovary. Key to the species of the genera Kannaphalus and Allopyragraphorus are provided.
Growth and reproduction of Xyrichthys novacula (Pisces: Labridae) in the Mediterranean Sea
Authors: Cardinale M. , Colloca F. , Ardizzone G. D.
Published: October 2008

Mediterranean razorfish, Xyrichthys novacula, were collected between July and December in a sandy bay of Ponza Island (Central Mediterranean Sea) to investigate the effects of reproduction and growth patterns on sexual inversion processes and haremic territoriality. The minimum body size of males decreased from 17 cm in July to 15 cm (T.L.) in October as a consequence of the sexual inversion after reproduction. Females showed a reproductive peak in August using both the Holden and Rait scale and the gonodosomatic index. The gonads of males were small, on average only 0.14% of total body weight. The proportion of body weight devoted to gonads did not change with male size. This is probably a consequence of the haremic mating system of the species which reduces sperm competition between males. A new coloration phase for females was introduced in addition to the three already described in the literature. Individuals of each age class are characterised by different coloration patterns. This chromatic feature of the species allows dominant males to recognize the age of females and consequently to choose during harem formation the older and larger specimens able to produce a larger number of offspring.
Salt effect on sensitized photooxidations. A kinetic approch to environmental decomposition of marine contaminants
Authors: Gutiérrez María I. , Criado Susana , García Norman A.
Published: October 2008

The salt effect on the kinetics of singlet molecular oxygen [O2(1Δg)]-mediated photooxidations of sea water contaminants was investigated. Two families of photooxidizable compounds were employed in the study: anthracene derivatives and phenols. The presence of salt (NaCl in H2O and LiCl in MeCN, in both cases in the range 0-0.45 M) produces changes in the photooxidation rate. For solvent-polarity-dependent reactions, this behavior can be predicted, by knowing the solvent-polarity dependence of the rate constant for chemical reaction of the substrates with O2(1Δ g) in non-saline solutions (kr). For the cases of photooxidations possessing solvent-polarity-independent or scantily-dependent kr values, the photooxidation rates decrease as the salt content in the solution increases, mainly due to a predominance of the physical quenching pathway. In addition, the quantum yield for O2(1 Δg) generation (ΦΔ) was determined in a series of saline solutions, in the range of 0-0.45 M in water and MeCN solutions, in the presence of NaCl and LiCl respectively. The Δ values are independent, within the experimental error on the salt content.
Growth of juvenile Pacific mackerel, Scomber japonicus in the Gulf of California
Authors: Gluyas-Millán María Georgina , Castonguay Martín , Quiñonez-Velázquez Casimiro
Published: October 2008

The otolith microstructure of juvenile (0-year) Pacific mackerel, Scomber japonicus, was examined to derive estimates of age, growth, and back-calculated hatching date distributions. Juveniles were collected from the Gulf of California between March 1990 and February 1996. Estimated ages of juveniles ranged from 27 to 111 days (31 to 162 mm SL). A Gompertz growth model provided a good description (r2= 0.85) of the length-at-age relationship. The maximum daily growth rate calculated was 1.91 mm d-1 for 44 day-old fish. The average growth rate up to 110 days old was 1.13 mm d-1. The back-calculated hatching date distributions showed that spawning occurs from November to May.
A re-description of Frillagalma vityazi Daniel 1966 (Siphonophorae, Agalmatidae)
Authors: Pugh P. R.
Published: October 2008

Ten complete specimens of Frillagalma vityazi Daniel, 1966 (Siphonophorae, Agalmatidae) were collected by the submersibles Johnson-Sea-Link I and II. These have allowed a more detailed description of the species to be made, as it was previously known only by its ill-preserved nectophores and one type of its bracts. The taxonomic status of the species is discussed. In addition much material has been identified from the Discovery collections, and the distribution of the species in the North Atlantic Ocean is considered.
On the fecundity of the Black Sea bream, Spondyliosoma cantharus (L. ), from the Adriatic Sea (Croatian coast)
Authors: Dulcic Jakov , Skakelja Neda , Kraljevic Miro , Cetinic Perica
Published: October 2008

The fecundity of the Black Sea bream from the eastern middle Adriatic (Croatian coast) was assessed by the volumetric method using 59 ovaries in pre-spawning stage from fish between 18.5 and 33.5 cm total length. Estimates of total potential annual fecundity varied between 31,670 and 554,070 eggs per female. Relationships between total potential fecundity and total length (TL), total weight (TW) and age (A) were established using the multiplicative regression model. Relative fecundity is constant, reaching a maximum of 850 eggs per g in the 30.5 cm to 31.0 cm length class.
Seasonal variations in the rate of photosynthetic activity and chemical composition of the seagrass Cymodocea nodosa (Ucr.) Asch.
Authors: Zavodnik N. , Travizi A. , De Rosa S.
Published: October 2008

Temporal changes in biomass, rate of photosynthetic activity and chemical composition of the seagrass Cymodocea nodosa (Ucr.) Asch., under the influence of various environmental factors, were followed in the Faborsa Bay, Northern Adriatic. Throughout the year the estimated average biomass was about 130 g dry wt m-2 with annual production of 80 g C m-2. In general, leaf length, biomass and production showed clear seasonality, with maximum values during the summer period (July-September) and clear minima in winter. Net oxygen production was closely related to biomass, leaf length, chlorophyll concentration, water temperature and incident light intensity. No clear seasonality was observed in the chemical composition (protein, fats, total phosphorus) of C. nodosa. Over the annual cycle, the range of measured variables was 10-16% for protein, 1.7-3.1% for fat, 0.3-0.8% for phosphorus, 1.6-2.6 for nitrogen in leaves, and 5-17% for protein, 0.9-3.2% for fat, 0.1-0.6% for phosphorus and 0.9-2.8 for nitrogen in roots.
Primary production and phytoplankton in three Galician Rias Altas (NW Spain): seasonal and spatial variability
Authors: Bode Antonio , Varela Manuel
Published: October 2008

Phytoplankton species composition, chlorophyll-a concentrations and primary production were studied in the Rias of Ares, Ferrol and the Bay of La Coruña (Galicia, NW Spain) in three oceanographic situations during 1993. The observations were representative of maxima and minima phytoplankton biomass and production values in this area during the seasonal cycle. A phytoplankton bloom studied in March, was characterized by a patchy distribution of chlorophyll and high primary production rates, especially near La Coruña and in the Ria de Ferrol. High phytoplankton biomass and production was also recorded in August, when an upwelling pulse allowed for enhanced growth. Diatoms were very abundant during these blooms but while Chaetoceros socialis was the dominant species in spring other species dominated in summer, when dinoflagellates and flagellates increased. In contrast, the phytoplankton observed in December had low abundances, and correspondingly low chlorophyll concentrations and primary production rates through the study area. Photosynthetic measurements at selected stations using P-I curves indicated that phytoplankton populations were well adapted to the existing light regime. The main source of variation in photosynthetic parameters was seasonal, and no significant differences resulted between rias. Using these parameters and the measured vertical profiles of chlorophyll and irradiance, areal estimations of primary production rates were made for the entire area studied. The resulting values were scaled to the rates measured using parallel simulated in situ incubations of phytoplankton. Maximum primary production values during blooms exceeded 2400 mg C m-2 d-1, whereas values estimated for the winter cruise were lower than 20 mg C m-2 d-1. These values are equivalent to those available for the nearby Rias Baixas, but because of the larger size of the latter the annual values of the studied Rias Altas were less than 10% of the reported primary production in the most productive Galician ria (Ria de Arousa). This study provides the first estimates of up-to-date primary production values for the Rias Altas, and points out the differential role of upwelling in the nearby shelf compared to its effects on the Rias Baixas region. Upwelling events occur in localized areas outside the Rias Altas, and their associated water dynamics may cause a large export of the produced organic matter to outer shelf areas. In contast, upwelling has been detected well inside most Rias Baixas, inducing high accumulations of recently produced organic matter, that are exported to nearby coastal areas.
A new species of Bathymedon Sars, 1892 (Amphipoda: Oedicerotidae) from the western Mediterranean bathyal floor
Authors: Jaume Damiá , Cartes Joan E. , Sorbe Jean Claude
Published: October 2008

Bathymedon longirostris sp. nov. (Amphipoda: Oedicerotidae) from the western Mediterranean bathyal suprabenthos is described. It is characterised by the well-developed rostrum; the discrete lateral lobe of head; the elongation of the peduncle segment 3 of the first antenna; the very slender propodus of the second gnathopod, which attains maximum width not at the palm angle, but at about midway along the palm margin; and by the relative length of the carpus of the foregoing limb, sub-equal to propodus. The discovery of a tiny remnant of the 2nd peduncle segment of the first antenna in the new species is commented with regard to the homologation of the peduncle segments in other members of the Family. The new taxon was captured below 593 m over muddy bottoms with pteropod shells and remains of planktonic foraminiferans. It was one of the most common amphipods in the lower slope (below ~ 1000 m), whereas in the depth range comprised between 1250 and 1859 m it was the second dominant species, representing 11.4 % of the total gammarideans captured. The area studied harbours three additional congeneric species, although their populations are mainly concentrated in the upper and middle slope. Over the bottom, adult males of the new species apparently tend to occupy higher levels beyond the water-sediment interface than the rest of demographic categories. The gut content of three individuals revealed a bulk of calcified foraminiferans, a diet in consonance with their massive mandibles. Juvenile individuals were more abundant in winter, whereas adult individuals were clearly dominant in summer, thus suggesting the biological cycle of the species follows some type of periodicity.
Down-regulation of Glial Fibrillary Acidic Protein (GFAP) during the development of a marine fish (Dentex dentex L.)
Authors: Busquest Xavier , Morales-Nin Beatriz
Published: October 2008

A band of approximately 52-53 kDa, corresponding to glial fibrillary acidic protein (GFAP) was detected by immunoblot techniques in brain tissue of a marine fish (Dentex dentex L). The aim of this study was to quantify the density of GFAP during the life cycle of a marine fish in the wild. The levels of GFAP immunoreactivity were determined at two different stages of development: juvenile (body weight range: 180-360 g) and sexually developing-mature specimens (body weight range: 2329-5550 g) from a natural population in the Western Mediterranean Sea. Our results indicated a negative correlation between the immunoreactivity of GFAP and weight in the sexually developing-mature group of fishes (r=-0.785, p
Egg and early larval development of laboratory reared dusky grouper, Epinephelus marginatus (Lowe, 1834) (Picies, Serranidae)
Authors: Glamuzina Branko , Skaramuca Bosko , Glavic Niksa , Kozvul Valter , Dulcic Jakov , Kraljevic Miro
Published: October 2008

The embryonic and early larval development of the laboratory-reared dusky grouper, Epinephelus marginatus (Lowe, 1834) are described and illustrated. The eggs, with a mean diameter of 846.68 ± 41 µm and a range from 736-940 µm, were spherical and transparent with transparent chorion. Embryonic development lasted 30 hours at 23°C. Newly-hatched larvae were 1.52 ± 0.066 mm in length. Absorption of the yolk sac was complete after the fourth day, when larvae reached 2.63 ± 0.123 mm in total length. The mouth opened 72 hours after hatching, and was in function after 96 hours, with an opening diameter ranging from 250-300 µm. Larvae had two fields of intensive pigmentation, one above the intestine, and the other between the anus and the end of the notochord.
First record of Gourretia denticulata (Lutze, 1937) (Crustacea, Decapoda, Thalassinidea) from the Atlantic coast of Spain
Authors: López de la Rosa I. , García Raso J. E. , Rodríguez Martín A.
Published: October 2008

The capture of a specimen of Gourretia denticulata (Lutze, 1937) (Decapoda, Ctenochelidae) from the Cádiz littoral zone, represents the first record of the species for Spain and for European Atlantic waters and confirms its presence in the East Atlantic Ocean. Some data on anatomic considerations and distribution are given.
Studies on the ecology and behaviour of the ghost crab, Ocypode cursor (L.) in northern Cyprus
Authors: Strachan P. H. , Smith R. C. , Hamilton D. A.B. , Taylor A. C. , Atkinson R. J. A.
Published: October 2008

Aspects of the ecology and behaviour of Ocypode cursor were studied on the beaches of Northern Cyprus. The crabs were widely distributed around the north coast of the island, occurring on 68 of the 77 sandy beaches investigated. At the main study beach at Alagadi, crabs occupied a band approximately 12 m wide; starting approximately 3 m horizontally from the edge of the sea (tidal fluctuation was minimal). Most small burrows occurred near to the sea, with the burrows of larger crabs predominating higher up the beach. Burrow numbers varied during the summer which was mainly attributable to variations in the numbers of burrows of juveniles. The sex ratio of emergent crabs also varied during the summer, possibly reflecting burrow oriented behaviour of reproductive females. There were strong correlations between burrow diameters and carapace lengths of the occupant crabs. There was a positive correlation between the presence of crab burrows and the number of people using sections of beach. The crabs were principally nocturnal, benefitting from food discarded by tourists. They also scavenged animal carcasses and were active predators of turtle eggs and hatchlings. Crab burrows usually had a single opening oriented towards the sea and those cast were L- or J-shaped. Burrows did not penetrate to the water table. The water content of the sand at the bottom of burrows was around 14 % by weight. Their burrows in the well-sorted sand provided the crabs with a thermally stable environment.
The first zoeal stage of Parthenope macrochelos (Herbst, 1790) hatched in the laboratory (Crustacea: Brachyura: Parthenopidae)
Authors: Guerao Guillermo , Abelló Pere
Published: October 2008

The first zoeal stage of the parthenopid crab Parthenope macrochelos is described and illustrated from laboratory-hatched material obtained from an ovigerous crab captured in the western Mediterranean. The first larva of P. macrochelos possesses all the characters as diagnostic of the Parthenopidae and some additional features, including a seta on the basal segment of the endopod of the maxillule and a well developed lateral spine on the telson forks. The present stage is compared with those previously described from other species of the genus Parthenope.
Lanternfish larvae from the Agulhas current (SW Indian Ocean)
Authors: Pilar Olivar M. , Moser H. G. , Beckley L. E.
Published: October 2008

This paper is presented as a guide to assist in identifying larval stages of lanternfish (family Myctophidae) of the Agulhas Current region. The work is based on the larvae collected during three cruises conducted off the eastern coast of South Africa from 29°S to 34°S in 1990 and 1991. The larval distributions obtained from these surveys are summarised briefly. Generally, only literature citations are given for species of the region whose larvae have been described previously. Descriptions are limited to those species for which complete larval development have not been published previously and to those species not known to spawn in the region, to compare larval features with those from regions where the species is known to spawn (i.e., Benthosema fibulatum, B. pterotum, Hygophum proximum, Lampadena luminosa, Myctophum selenops, Notoscopelus caudispinosus and Triphoturus nigrescens). Also, diagnostic characters and illustrations are presented for species which may be difficult to identify in some developmental stages, particularly the early larval stages (i.e., Benthosema suborbitale, Bolinichthys spp., Ceratoscopelus townsendi, Diogenichthys panurgus, Myctophum phengodes, Lobianchia dofleini, L. gemellarii and Scopelopsis multipunctatus).
Dispersal strategies of benthic species and water current variability in the Corsica Channel (Western Mediterranean)
Authors: Aliani Stefano , Meloni Roberto
Published: October 2008

Four seasonal surveys were carried out in the Gulf of Tunis between summer 2002 and spring 2003 to study the abundance and distribution of Sardina pilchardus eggs and larvae in relation to environmental parameters. In the Gulf of Tunis, Sardina pilchardus begins spawning in autumn (23 eggs/10 m²) and attains its peak in winter (257 eggs/10 m²) when the mean SST is lowest (13.4°C). Sardine reproduction seems to be triggered by the decrease in the SST. In winter, the main spawning areas were located to the south of Zembra Island and the north of Cape Bon. Larvae were more abundant in winter (38 larvae/10 m²), while lower densities were collected in autumn and spring (1 larva/10 m²). The highest abundance of larvae (288 larvae/10 m²) was recorded southwest of Zembra Island. Eggs and larvae were mainly concentrated in the relatively warmer and saltier waters with high zooplankton abundance and, inversely, with a low concentration of nitrate and chlorophyll a and a low diatom abundance.
Fish Attraction Devices (FADs) and experimental designs
Authors: Kingsford Michael J.
Published: October 2008

There is widespread use of fish attraction devices (FADs) in commercial fisheries and research. Investigations on the utility of FADs to catch fishes, and factors influencing fishes associated with FADs, require careful consideration of experimental designs. The development of appropriate models, from observations and the literature, should be developed before hypotheses can be tested with robust sampling designs. Robust sampling designs may only be possible if investigators have some role in the planning stage of deploying FADs. If the objective of the study is to determine the influence of FADs on assemblages of fishes, then experimenters need to consider that a `FAD-effect´ (=impact) cannot be demonstrated without controls. Some preliminary studies may be required to determine the spatial extent of a FAD-effect before suitable sites can be chosen for controls. Other controls may also be necessary, depending on the method used to estimate numbers of fishes (e.g. controls for disturbance). Recent advances in sampling designs that are applicable to impact studies are discussed. Beyond-BACI (Before After Control Impact) and MBACI (Multiple BACI) designs are recommended because they cater for temporal and spatial variation in the abundance of organisms, which is generally great for pelagic fishes. The utility of orthogonal sampling designs is emphasised as a means of elucidating the influence of multiple factors and, importantly, interactions between them. Further, nested analyses are suggested to deal with multiple temporal and/or spatial time scales in sampling designs. The independence of replicate FADs should also be considered. Problems of independence include: FADs that are connected, thus providing potential routes of movement of associated fishes; temporal dependence where the number of fish at a time influences the number at the next time due to fish becoming residents; and the fact that the proximity of other FADs may influence numbers of fishes. Solutions to these problems are suggested. The recommendations in this paper are relevant to investigations on pelagic fish of all sizes, with and without FADs.
Fish communities associated with FADs
Authors: Deudero S. , Merella P. , Morales-Nin B. , Massutí E. , Alemany F.
Published: October 2008

Two groups of six fish aggregating devices (FADs) were deployed at two locations off the eastern coast of Majorca (Western Mediterranean). Samples were obtained fortnightly throughout a two-year period by means of hauls performed with an experimental purse seine. Two control areas were established to check the aggregation efficiency of the FADs. A total of 16 families and 26 species of fishes were recorded beneath FADs. Pelagic fishes, largely Trachurus picturatus, T. mediterraneus, T. trachurus, Naucrates ductor, Seriola dumerili and Coryphaena hippurus, dominated the fauna. The total fish abundance, number of species and length range of the species confirmed that the FAD community was significantly related to season (recruitment period), resulting in a sequential fish colonisation of the FADs during the study period. Some of the species were present only during a particular period, such as Trachurus spp. in spring and summer. Other species, although evident for a longer period, were more occasional in catches (Schedophilus ovalis, Balistes carolinensis and Polyprion americanus), and some others were also present in small quantities. Diversity and equitability of the fish community associated with FADs were higher in summer than in winter. Many species were more abundant around FADs than in open water controls. The species that showed the most distinct recruitment phase beneath the FADs were N. ductor, S. ovalis, Trachurus spp., P. americanus, S. dumerili, C. hippurus and B. carolinensis. FADs can be considered nursery structures for many pelagic and demersal species, thus having an effect on the redistribution of juveniles. In the deployment of artificial structures as aggregators for fishing purposes one should consider the patchiness and seasonal characteristics of these communities as well as the redistribution aspect for fishery management.
Traditional and experimental floating fish aggregating devices in the Gulf of Castellammare (NW Sicily): results from catches and visual observations
Authors: D'Anna G. , Badalamenti F. , Riggio S.
Published: October 2008

Floating fish aggregating devices (FADs) have long been used to attract fish in NW Sicily since antiquity. Recently, a number of changes have been made to the type of material employed to construct FADs, with the aim of increasing their effectiveness. In this paper we compare the catches made at eight experimental floating FADs (polypropylene ropes frayed at the ends) with those obtained at eight traditional FADs in the Gulf of Castellammare. A total of 672 samples were collected during summer and autumn in 1995 and 1996 at the 16 FADs using a surrounding net. Visual observations of fishes associated with the FADs were also conducted to obtain qualitative information about the spatial distribution of species. A total of 1632 specimens weighing 144 kg and belonging to eight species were caught during the survey. Seriola dumerili, Caranx crysos, C. rhonchus and Coryphaena hippurus were the most frequent and abundant species accounting for 96% of the total catch. Average fish abundance and weight, characterised by high variance, were significantly higher at the sites with experimental FADs than at the sites with traditional FADs. S. dumerili was the only species with higher catches around the experimental FADs. Some spatial and temporal variations in fish abundance and size were also detected. Younger individuals of S. dumerili were observed to show high affinity for the experimental FAD tufts.
Fish fauna associated with floating objects sampled by experimental and commercial purse nets
Authors: Massutí Enric , Morales-Nin B. , Deudero Salud
Published: October 2008

Based on the commercial surrounding nets traditionally used in the Coryphaena hippurus fishery, we designed an experimental purse seine (64 m long and 14 m high, with a purse line and a central codend of 2 mm mesh) for sampling fish fauna associated with flotsam. Taxa, number, biomass and sizes of fishes caught with both types of gear around fish aggregation devices were compared. From 63 hauls with the experimental net, we caught 11370 fishes belonging to 17 families and 26 species. In contrast, 816 fishes belonging to 7 species and 5 families were collected from 39 commercial hauls. Despite differences in number of hauls for each net, the curves of cumulative species richness showed that additional hauls could not increase the number of species collected with the commercial net. The most abundant species from experimental net catches were Trachurus picturatus, which represented over 80% of the specimens caught in spring and summer, Naucrates ductor, which represented about 50% of autumn catches, both in terms of abundance and biomass, and Seriola dumerili, which represented 46% and 21% of the samples taken in summer and autumn respectively. Seriola dumerili was also frequent in commercial net catches, in which T. picturatus did not appear, while Coryphaena hippurus and N. ductor represented more than 85% of both abundance and biomass. Large differences between the two types of net were also obtained in the mean fish weight and length frequency distributions of the catches by season. Fish caught with the experimental net ranged from 6 to 570 mm length, while fish collected from commercial hauls had a size range of 35 to 700 mm. The effectiveness of the experimental net in catching small fishes showed that it can be an optimal sampling method not only in the study of fish fauna associated with flotsam, but also in studies to catch early life stages.
Ichtyofauna associated with drifting floating objects in the Balearic Islands (Western Mediterranean)
Authors: Riera Francisco , Grau Amalia , Grau Antonio M. , Pastor Elena , Quetglas Antoni , Pou Sebastián
Published: October 2008

Species composition, size range and some behavioral notes about drifting flotsam associated fish of the Balearic Islands are presented, and more detailed observations on Seriola dumerili, Naucrates ductor, Coryphaena hippurus and Scomberesox saurus are also given. 25 fish species belonging to 18 families were identified, 12 of these species and the individuals of the family Mugilidae were recorded for the first time associated with floating objects in the western Mediterranean. Most of the specimens collected were juveniles, which suggests the importance of floating objects as a nursery, and thus in the recruitment and redistribution of fishes. Analisis of two drift floating material samples show that objects of anthropogenic origin were most abundant (83.5% and 63.5%) and suggests that at present, human refuse may have taken over the role of the floating remains of marine plants for fishes in the western Mediterranean pelagic environment.
Apparent habitat extensions of dolphinfish (Coryphaena hippurus) in response to climate transients in the California Current
Authors: Norton Jerrold G.
Published: October 2008

Dolphinfish, Coryphaena hippurus, a globally distributed, fast growing, predatory species has extended its habitat poleward off the west coast of North America in response to atmosphere-ocean climate transients that can be measured throughout the Pacific Ocean basin. Poleward habitat extension is measured by the availability of dolphinfish to southern California Commercial Passenger Fishing Vessel (CPFV) anglers. Before 1972 the annual CPFV dolphinfish catch during the July-October fishing season seldom exceeded a few hundred fish. Thereafter, more than 103 dolphinfish were taken in 23 of the next 25 seasons. The next shift was in 1990 when catch exceeded 3.0 x 104 fish. More than 2.0 x 104 fish were reported in three of the next seven seasons. The apparent habitat extension coincides with increased ocean temperatures, forced by increases in North Pacific cyclogenesis and increases in downwelling coastal-trapped long wave transmission from the equatorial ocean. Interannual analysis shows that habitat expansion is associated with a decrease in upwelling off northern Mexico, which may be locally or remotely forced. Dolphinfish habitat shifts poleward in response to Pacific climate transients, reflecting global environmental trends. If subtropical ocean surface layers continue to warm throughout the world, as observed off southern California and northern Mexico, a global increase in the dolphinfish habitat is expected.
The ecology of and fishery for Coryphaena spp. in the waters around Australia and New Zealand
Authors: Kingsford Michael J. , Defries Anthony
Published: October 2008

Two species of dolphinfish, Coryphaena hippurus and Coryphaena equiselis, are found in Australian waters and off the north-eastern coast of New Zealand. Both species (also called Mahi-mahi, or dorado) are generally found in tropical waters, but only C. hippurus is captured in southern waters (to 34°S). Dolphinfish are caught by recreational and commercial fishers, using either trolled or baited lines. Most catch records do not allow the identification of fish to the species level. Dolphinfish are also an incidental catch of foreign and domestic pelagic fisheries (e.g. long-lining for tunas and billfishes) and 10-70 tonnes are taken per year in the Australia-New Zealand region. Although Coryphaena are known to associate with objects (e.g. traps for carangids and navigation buoys) and are a focus for recreational fishers, Fish Attraction Devices (FADs) are not used by commercial fishers off the coast of Australia and New Zealand. FADs are, however, used by fishers in the Pacific Islands. Recreational catches of Coryphaena may exceed the commercial catch in some areas. Good data for New South Wales, Australia, gave estimates of 11.7 and 12.7 tonnes of Coryphaena caught in 1994 and 1995 respectively, which represented 1.1-1.8x the recorded commercial catch. Approximately ~12,600 fish have been tagged since 1973 around Australia and data on returns are only available for 108 fish (0.86% recovery). Tagged Coryphaena were found to move distances of up to 440 kilometres and at estimated speeds of up to 20 kilometres per day. The time between tag and recapture varied from 0-360 days and fish moved 0-440 kilometres. The majority of fish were caught around the same drifting object near where they were tagged. The collection of Coryphaena larvae in Queensland and New South Wales, along the east coast of Australia, indicates spawning in these waters. Most larvae have been collected in the austral summer and autumn and typically in surface waters well offshore. Dolphinfish have been successfully raised from eggs to fish of marketable size in Western Australia and the species appears to be an excellent candidate for mass production, which is now possible in Australia.
Biology of the dolphinfish (Coryphaena hippurus) in the western central Atlantic: a review
Authors: Oxenford Hazel A.
Published: October 2008

The dolphinfish, Coryphaena hippurus, is a circum-tropical oceanic epipelagic species which is of significant importance to both commercial and sport fisheries in the western central Atlantic. Despite this, little attention has been paid to conducting biological stock assessments and developing management strategies for this species, and it remains unmanaged across most of the region. This paper summarizes aspects of the biology of dolphinfish that are relevant to assessment and management from studies of this species in the southeastern United States, Gulf of Mexico and the Caribbean. Throughout their range in the western central Atlantic, dolphinfish are seasonally abundant and presumed to be highly migratory. They exhibit high growth rates, early maturity, batch spawning over an extended season, a short life span and a varied diet. Marked differences in some biological characteristics and in the frequency of IDH-2 alleles between dolphinfish from the southeastern USA and the Caribbean suggest a relatively complex stock structure for this species, which needs further investigation to improve the information base for development of management strategies for dolphinfish across this region.
Feeding habits of the dolphinfish (Coryphaena hippurus) in the eastern Caribbean
Authors: Oxenford Hazel A. , Hunte Wayne
Published: October 2008

The dolphinfish, Coryphaena hippurus, is an oceanic epipelagic fish with economic importance to sport and commercial fisheries throughout its worldwide distribution in tropical and sub-tropical waters. In the eastern Caribbean, dolphinfish are generally piscivorous, eating a wide variety of fish species including small oceanic pelagic species (e.g. flyingfish, halfbeaks, man-o-war fish, sargassum and rough triggerfish), juveniles of large oceanic pelagic species (e.g. tunas, billfish, jacks, dolphinfish), and pelagic larvae of neritic, benthic species (e.g. flying gurnards, triggerfish, pufferfish, grunts). They also eat invertebrates (e.g. cephalopods, mysids, scyphozoans), suggesting that they are essentially non-selective foragers. This appears to be typical of dolphinfish from other locations and of tropical oceanic pelagic species in general. Post-larval flying gurnards and flyingfish rank as the most important prey species overall. However, the diet varies with season, and mysids are a very important component from October to December. Diet also varies slightly with predator size (small dolphinfish eat fewer flyingfish and more squid than larger sized dolphinfish), and with sex (males take proportionally more of the active, fast swimming species such as flyingfish, squid and dolphinfish than do females). From these results and a review of the literature to determine the diet of other tropical oceanic species and the predators of dolphinfish, it can be seen that predator-prey relationships and interspecies competition for food clearly involve other commercially important species. As such, interactions between the surface trolling dolphinfish fisheries, the surface gillnet flyingfish fisheries, and the subsurface longline tuna fisheries in the eastern Caribbean can be expected.
Population size structure, age and growth of Naucrates ductor in the small scale FADs fishery of Mallorca Island (western-Mediterranean)
Authors: Reñones O. , Morales-Nin B. , Deudero S.
Published: October 2008

The pilotfish (Naucrates ductor) is mainly caught as a by-catch of the dolphinfish fishery using FADs deployed around Mallorca (western-Mediterranean) from the end of August to December. The age and growth parameters of this species were estimated by length frequency analysis and daily growth increments observed in the otoliths. To validate the daily formation of the ring observed in the sagittae otoliths, a marking otoliths experiment with SrCl2 was carried out with juvenile specimens kept in laboratory conditions. The growth parameters obtained from otolith interpretation were based on age at length of 99 specimens ranging between 15 and 31.2 cm FL. Length frequency analyses were based on the monthly length distribution obtained in 1990, 1991, 1995 and 1996. The results obtained from the two methods were similar and showed rapid growth during the first 6 months of life. The von Bertalanffy growth equation from otoliths was FL= 28.97 (1-e (-6.87(t - 0.055)). Positive allometric growth was observed in the length-weight relationship, with no differences existing between sexes: W (g)= 0.0147*FL3.040 (cm).
Review of dolphinfish biological and fishing data in Japanese waters
Authors: Sakamoto Ryoichi , Kojima Shumpei
Published: October 2008

The dolphinfish (Coryphaena hippurus) performs seasonal migrations into adjacent waters of Japan, where it is exploited by several fisheries. The annual dolphinfish landings in Japan have tended to decrease in recent years. Between 1993 and 1995, the mean annual catch was 9962 metric tonnes. This total catch corresponded to the following fishing methods: set net fishery 24.9%, skipjack pole and line fishery 21.2%, surrounding net fishery (which is mainly comprised of the shiira-zuke fishery) 12.9%, longline fishery 10.2%, other angling fisheries 10.3%, and other fisheries 20.5%. In the shiira-zuke fishery, fishermen catch dolphinfish and other fishes gathering around bamboo rafts (called tsukegi) with a purse seine net. Major fishing grounds of this fishery are situated in the western Japan Sea and off the south Pacific Japanese coast. The use of floating FADs to create productive fishing areas is of ecological interest. In this paper we describe this fishery, and review the biological characteristics of dolphinfish with regard to ecology and fishing conditions.
Precautionary assessment and management of dolphinfish in the Caribbean
Authors: Mahon Robin , Oxenford Hazel A.
Published: October 2008

Dolphinfish in the Caribbean are fast growing and short-lived, living for about 12 to 18 months in the southern Caribbean and a maximum of 2-3 years in the north of the region. They are believed to be highly migratory, are seasonally abundant, and likely to have a more complex stock structure than the larger oceanic epipelagic species. Most of the information on dolphinfish in the western central Atlantic comes from studies in the waters of the USA and the eastern Caribbean, and there is a general paucity of information particularly for stock-based management of this species. No Caribbean country undertakes regular assessment of dolphinfish, or has put in place any species-specific management program. Yield-per-recruit analyses for this species in the eastern Caribbean suggest that maximization of Y/R is likely to lead to very low levels of mature stock biomass. A stock recruitment analysis does not show any dependency of recruitment on stock size within the observed stock size range. This suggests that recruitment failure could be sudden at some threshold below the minimum observed stock size, probably at about one third of the average observed stock size. Given the trends observed in landings of dolphinfish, a precautionary approach to management is needed for this species in the western central Atlantic. Given the migratory, shared nature of the dolphinfish resource, a regional approach to assessment and management is required. However, the institutional basis for this approach does not currently exist within the region in a form that is functional. The membership of the International Commission for the Conservation of Atlantic Tunas (ICCAT) does not include any of the small island states where dolphinfish is of primary importance. ICCAT would need to establish a regional presence in order to serve the needs of Caribbean states. The FAO Western Central Atlantic Fishery Commission (WECAFC) does not operate in a mode which would allow it to address this issue. The Association of Caribbean States is too new to address it within the near future. Subregional organizations with fisheries programs, such as the Caribbean Community (CARICOM) and the Organisation of Eastern Caribbean States (OECS), represent only a subset of states. However, given the ratification of United Nations Convention on the Law of the Sea (UNCLOS) and the recent International Agreement on Highly Migratory Stocks and Straddling Stocks, these organisations could take the initiative to establish a regional management programme for dolphinfish.
Population dynamics and fishery of dolphinfish (Coryphaena hippurus) in the western Mediterranean
Authors: Lleonart Jordi , Morales-Nin Beatriz , Massutí Enric , Deudero Salud , Reñones Olga
Published: October 2008

The dolphinfish (Coryphaena hippurus) fishery based on the island of Majorca (western Mediterranean) and the population dynamics of the species were studied between 1995 and 1996. Fishing effort, landings and length composition of the catches during the sampling period, as well as the historic catch data series and fleet were analysed. Virtual Population Analysis (VPA), taking as the time unit the week in 1995 and the fortnight in 1996, were also carried out. Dolphinfish is fished from August to December, with main catches in September-October, using anchored fish aggregation devices (FADs) and surrounding net. The mooring areas, placed from 70 to 1200 m depth, are distributed among the boats registered for the year´s fishery. A total of 46 boats took part in this fishery in 1995 and 37 in 1996, with a catch of 128 and 52 metric tons respectively. These wide fluctuations are also shown in the annual catches of the 16year series, which ranged from 2 to more than 120 metric tons, showing a slightly increasing trend (4 tons per year). The comparison of different measures of effort (FADs, days and hours) showed similar values of CPUE, although the number of FADs showed the lowest variation, with normal variances and average values not significantly different between harbours. The length composition of the catches ranged from 20 to 64 cm fork length, which corresponds to juveniles between 2 and 6 months of age. The main results of the VPA, which must be regarded in relative rather than absolute values, showed that the available population and the recruitment in 1995 are greater (around one order of magnitude) than in 1996. For both years, the number of individuals declined in the course of the fishing season, while biomass increased during the first 5 weeks. The fact that the exploited fraction of the dolphinfish population is composed of 0-age class suggests that catch fluctuations might be related to environmental parameters and to the migratory behaviour pattern of the species. These two interrelated factors can produce failures of its annual spawning in the western Mediterranean, and/or of the recruitment of the species to the fishery.
Economic aspects of fishing of dolphinfish in Sicily
Authors: Cannizaro L. , D'Andrea F. , Potoschi A. , Scalisi M.
Published: October 2008

Dolphinfish fishing with Fish Aggregating Devices (FADs) and purseseine nets is normally practised everywhere in Sicily and the Pelagic Archipelago. The fishing season starts in July when the FADs are placed and finishes in December. In the 1996 fishing season, in 5 sample ports, catches and fishing effort were taken through interviews during landing, fishing running costs were taken by interviewing fishermen and prices per kilos paid to fishermen were taken through direct observation. Catches, costs and profits per sample port, per week and for the entire fishing season were then calculated or estimated. Though it is freshly marketed only in Sicily, the resource would appear to provide a lucrative activity.
Small-scale Tunisian fishery for dolphinfish
Authors: Zaouali Jeanne , Missaoui Hechmi
Published: October 2008

In this note we describe the dolphinfish (Coryphaena hippurus) fishery off Tunisian waters (central Mediterranean). Dolphinfish is fished from late August to early December, with the main catches in September-October, using fish aggregation devices and surrounding nets. A total of 260 boats are devoted to this fishery along the whole Tunisian coast, with an average annual catch of around 300 metric tonnes. The main fishing areas and ports are located on the central-eastern coast, which concentrates around 70-75% of fishing effort and landings. Both the sesonality of the fishery and the length composition of the catches, with a clear increase in mean size during the fishing period (from 26.0 cm fork length in August to 44 cm fork length in December), are similar to those reported in other Mediterranean areas.