Hasil untuk "Aquaculture. Fisheries. Angling"

T.S. Silva, L.E.C. Conceição, Ø. Sæle et al.

Ballan wrasse is a widely used cleaner fish for farming Atlantic salmon and is collected from nature and reared for this purpose. One of the main bottlenecks in ballan wrasse rearing is formulation of diets that result in high feed intake, growth, and health. The problem is believed to be related to poor acceptability of diets and functional properties of the agastric, short digestive system of the species. The aim of this study was to improve understanding of digestive functions as basis for making better feed and improving overall production performance.For this purpose, we developed a mechanistic dynamic model that quantifies digestion, absorption, and retention efficiency of selected macronutrients in ballan wrasse. Dynamic models are powerful tools for integrating practical data from experiments with hypotheses, theoretical concepts, and literature data in an iterative process that clarifies and controls experiments, hypotheses, and designs. Due to its mechanical nature, the ballan wrasse model can be easily adapted to other fish species.The model was calibrated with previously published results where the fish were fed diets with added inert markers to follow digestion, absorption, and evacuation rate. The model overestimated protein digestibility/absorption (Apparent Digestibility Coefficient; ADC) in the first intestinal segment (S1) but showed good compliance for the rest of the intestine. Both the model and experimental data showed that a large fraction of protein absorption ADC-P was in S1. For lipids, both S2 and S3 contributed more to ADC-L. The gut transit time was calculated after feed change and was 12–14 h. It took 4–8 h for 90 % of the feed to move from S1 to midgut (S2). At this time, 7 % of the intestinal contents had entered the hindgut (S4). The model simulates transit of S4 well, but underestimates transfer rate from bulb (S1) to anterior midgut (S2).

Berenice Suárez-Puerto, Marcelo Araneda, Mariel Gullian-Klanian

This study presents a bioeconomic model after analyzing the commercial profitability of Nile tilapia under biofloc (BFT) and green water (GWT) technologies. Environmental stochasticity was evaluated using the parameters obtained in Yucatan's rainy (RN) and dry (DR) seasons. The productive impact was measured by analyzing the 10-year cash flow. Both systems demonstrated profitability with a positive NPV and 450 g harvest weight in the short term. The unit cost of production results for the GWT was lower than for the BFT. The long-term simulation involved an investment of $410,279 USD for 30 tanks, resulting in a positive return for GWT. BFT showed negative long-term profitability at the current selling price ($2.36 USD/kg). Profitability improved as the sales price increased by 11% and 22% for RN-BFT and DR-BFT, respectively. This bioeconomic model is pioneering in tilapia production in BFT and GWT and provides valuable data to achieve better yield and profitability.

MING-CHIH HUANG

A female tuna of odd appearance, with the size of a Pacific bluefin tuna (Thunnus orientalis Temminck and Schlegel, 1844), anal fin count of bigeye tuna (Thunnus obesus Lowe, 1839), pectoral fins of yellowfin tuna (Thunnus albacares Bonnaterre, 1788), caught in waters west of the island of Xiaoliuqiu, Pingtung, Taiwan, received considerable media attention after its landing at Tungkang fishing port on 14 December 2020. This tuna has now been identified by molecular systematic means. Fishermen and fish merchants suggested it was a hybrid form, unique in living memory; however, it had matured ovaries and developing ova. To confirm whether this fish was a hybrid, we determined its parental species by analysing the cytochrome b gene (cyt b) and cytochrome c oxidase subunit 1 (COI) sequences of the mitochondrial DNA for maternal inheritance, and the internal transcribed spacer 1 (ITS1) gene sequence from the nuclear DNA to confirm both parents’ lineages. Genomic DNA was isolated from fast-skeletal muscle, and primers were designed based on the known sequences of conserved regions among tunas. According to cyt b and COI, the mother of the peculiar tuna was a Pacific bluefin tuna (T. orientalis), and the ITS1 sequence showed that both parents were of this species. We therefore conclude that despite the mixed morphological appearance, this abnormal tuna was a Pacific bluefin tuna, not a hybrid.

Wenhua Chu, Huiqin Guo, Huaizhi Zhang et al.

In order to study the influence mechanism of structural type and size on the hydrodynamic performance of vertical curved V-type otter board, this paper based on the computational fluid dynamics method, a three-dimensional numerical model of vertical curved V-type otter board is established to calculate and analyze its hydrodynamic performance, and the validity of the numerical simulation results is verified by designing and constructing a scaled model for dynamic flume experiments. On this basis, the effects of different structural parameters, such as the deflector angle, camber, and spacing, on the hydrodynamic performance of the vertical curved V-Type otter board are investigated and the optimal structural design scheme is determined. The results demonstrate that single or synchronous changes of the angle, camber, and spacing of the two deflectors have varying degrees of impact on the hydrodynamic performance of the vertical curved V-Type otter board. To improve the expansion effect of the otter board, setting the angle of the deflector A to 40° and that of the deflector B to 30°, or setting the camber of deflectors A and B to 18%, or setting the spacing between deflectors A and B to 380 mm and that between the deflector and the main panel to 670 mm can increase the lift coefficient of the vertical curved V-Type otter board to its maximum value. Considering the overall performance of the otter board, when the angle of the deflector A is set to 25° and that of the deflector B is set to 30°, or the camber of the deflector A is set to 6% and that of the deflector B is set to 9%, or the spacing between deflectors A and B is set to 340 mm and that between the deflector and the main panel is set to 610 mm, the lift-to-drag ratio of the otter board can be increased to its maximum value.

Tkachenko Halyna, Kasiyan Olha, Kamiński Piotr et al.

The current study assessed health risks posed by exposure to metals from the consumption of Baltic Sea trout (Salmo trutta L.). Concentrations of essential minerals in sea trout muscles were determined and compared with the physiological requirements of these minerals in Polish nutrition standards, recommended dietary allowances (RDA), and estimated average requirements (EAR). Chemical analyses indicated that sea trout was rich in phosphorus, calcium, magnesium, sodium, and potassium. The pattern significance gradation of the element concentrations was as follows: P>Ca>Mg>Na>K>Fe>Zn>Cu>Se>Mn>Co. Sea trout consumption can provide a considerable portion of the RDA of copper, magnesium, phosphorus, calcium, iron, and zinc. The ranking order of the mean toxic element concentrations in sea trout muscle tissues was As>Pb>Cd>Hg. Potential risk estimated with the hazard quotient (HQ) indicated that most metals posed no health risk because they did not exceed reference doses at HQ < 1. For carcinogenic and non-carcinogenic effects, the maximum allowable rates of sea trout consumption were sufficiently high to ensure human health. According to these data, the consumption of farmed sea trout from the Baltic Sea in the northern region of Pomerania, Poland did not pose a risk to human health.

Leni G. Yap-Dejeto, Melodina Fabillo, Marilou Sison-Mangus

Sargassum is the most diverse genus in the brown algal order Fucales, which is an ecologically important primary producer in marine ecosystems. The Philippines has about 73 species of Sargassum identified based solely on morphology, representing 18% of its reported global diversity. The genus is known for its morphological plasticity which makes identification of its species challenging. Taxonomy is particularly problematic in the Philippines where molecular data for Sargassum is lacking. We collected 34 samples of Sargassum from Eastern Samar, Philippines, an area known to have significant species diversity. Using newly designed primers to amplify the nuclear ribosomal internal transcribed spacer (ITS) region, we generated gene sequences and reconstructed the phylogeny of Sargassum to infer species diversity of the Eastern Samar samples. Based on morphological assessments of samples, we found S. corderoi, S. polycystum and five other morphotaxa. Molecular assessments, on the other hand, show the presence of only three morphotaxa. Bayesian inference, maximum parsimony and maximum likelihood generated almost identical trees which showed that S. corderoi and Sargassum sp. aff. siliquosum samples are nested in a clade of S. ilicifolium. This is the first time that S. corderoi has been reported in Eastern Samar. Another species, S. polycystum, formed a clade consisting of well-supported subgroups. This study is a step towards updating the taxonomic identification of Sargassum species found in the Philippines using molecular and morphological data. The biomarker used in our study could improve the identification of Sargassum species in a species-rich subtropical-tropical geographical area such as the Philippines, in phylogenetic studies of Sargassum.

Anne-Laure CHATEIGNER-BOUTIN, Luc SAULNIER, Michel LESSIRE et al.

Les polysaccharides à base de mannose sont très largement répandus dans le monde vivant. D’un organisme à un autre, la longueur du squelette de mannose, le type de liaison entre les sucres, la composition et la longueur des ramifications sont extrêmement variables et confèrent à ces polymères des propriétés fonctionnelles et biologiques différentes. Au-delà de leur rôle structural ou encore de capteur de molécules d’eau dans les plantes, ils participent en particulier à la glycosylation des protéines et sont clairement impliqués dans les phénomènes d’interaction ligand-récepteur. Certains polymères de mannose viraux ou bactériens hautement conservés sont ainsi, chez les animaux supérieurs, reconnus très rapidement par l’hôte qui se défend en initiant une réponse non spécifique, dite « réaction immunitaire innée ». Plutôt reliées par les liaisons α chez les virus, les bactéries et les levures, les unités de mannose sont reliées par des liaisons β chez les végétaux supérieurs. Les β-mannanes sont présents dans tous les produits d’origine végétale, et à des teneurs particulièrement élevées dans certaines familles (palme, guar, coprah) et certains tourteaux utilisés en alimentation animale. Leurs propriétés anti-nutritionnelles observées chez les porcs et les volailles s’expliqueraient principalement par l’apparition d’inflammation intestinale induisant des baisses de performances, des baisses d’efficacité alimentaire et une augmentation des dépenses énergétiques associées à la mise en œuvre du système immunitaire.

Mitsuharu Yagi

To study the effects of a typhoon on a temperate, coastal bay community, the species composition, catch amount, and diversity of epipelagic fish assemblages were investigated. Fish samples were taken from catches of a purse seine fishery in Tachibana Bay, Japan between May and July 2011, covering before and after the passage of a typhoon in the area. Although major changes in total catch amount were not observed before and after the passage of the typhoon, the abundance of the Japanese anchovy, Engraulis japonicus Temminck et Schlegel, 1846, markedly decreased and bycatch of species increased, accompanied by increasing levels of diversity of the fish assemblage. Multivariate analysis showed that community differences before and after the passage were quantitative rather than qualitative. Comparisons in total length frequencies between the two periods indicated that specimens of the species compared were bigger in size for Trachurus japonicus (Temminck et Schlegel, 1844) and smaller for E. japonicus in the “after” period. These results suggest that the passage of the typhoon triggered not only interspecific faunal change but also intraspecific recruitment shifts in and around the bay.

Yu. I. Zuenko, N. L. Aseeva, S. Yu. Glebova et al.

Recent changes of the main oceanographic, chemical, and biological parameters of the Okhotsk Sea ecosystem are considered briefly for the last decades (2000–2010s), mostly on the data obtained in marine expeditions conducted by Pacific Fish. Res. Center (TINRO) annually. Since the mid-2000s, anomalous oceanographic conditions were formed there with prevailing heightened temperature in all layers of the sea and lowered ice cover caused by changes in the atmosphere circulation with northward shift of cyclones tracks in winter and weakening of winter monsoon. The ice cover was below the normal value every year since 2004. In the warmer winter conditions, producing of the high-density water on the northern shelf decreased from 3.2–7.8 . 103 km3 in 1998–2002 to 1.2 . 103 km3 on average in 2004–2015, and the water with density sq &gt; 26.8 was not formed at all in 2007–2009, 2011, and 2014–2015. As the result, winter convection, including the slope convection, became weaker and shallower and ventilated worse the water column, so dissolved oxygen content decreased in the lower portion of the intermediate layer, usually ventilated by slope convection. For the core of the intermediate layer (isopycnal surface 27.0 σθ), positive trend of temperature is estimated as +0.04…+0.16 o/decade, by areas, while the trend of dissolved oxygen content is negative: –0.07…–0.14 mL/L.decade, by areas. From the other hand, spring phytoplankton bloom became less intensive, presumably because of poorer upward flux of nutrients in conditions of weaker vertical mixing, and zooplankton biomass decreased, particularly for phytophages. However, these changes did not cause significant response in fluctuations of stocks for the main commercial fish and crab species. The largest stock of walleye pollock had cyclic fluctuations driven mostly by intra-population regulations, the stocks of pacific herring were rather stable, and the stocks of deep-water fish species, as flounders and halibuts had a slight tendency to growth, possibly because of better conditions for reproduction. Indeed, the densest aggregations of greenland halibut shifted from the depth of 600–700 m to 500–600 m that may be caused by de-oxygenizing of the lower portion of the intermediate layer. Crabs abundance also had positive dynamics obviously because of the effect of protective measures for red king crab in the 2009–2012, though its biomass continued to grow even after restoring the commercial landings. There is concluded that recent changes in the macroecosystem of the Okhotsk Sea correspond to the conception of the sub-polar ecosystems transformation under climate warming toward decreasing of their productivity and increasing of their functioning efficiency that was proposed earlier for the Japan Sea. Thus, from position of commercial exploitation of marine biological resources, the modern reconstruction of the Okhotsk Sea ecosystem under the climate change impact could be considered as a positive process.

Harry VERMULM Jr, Maria GIAMAS, Elmar CAMPOS et al.

Através da coleta de dados mensais de captura foi realizado o acompanhamento da produção da pesca extrativa nos rios Paranapanema, Paraná, Grande, São José dos Dourados, Turvo e na Represa de Três Irmãos (rio Tietê), no perí­­odo de 1994 a 1999, e no rio Mogi Guaçu, em Pirassununga, somente no ano 1994. A amostra total da captura consistiu em 4.298,1 t, sendo que o rio Paraná contribuiu com 2.565,5 t (59,69%), o rio Grande, com 1.298,5 t (30,21%), o rio Paranapanema, com 288,0 t (6,70%) e os demais, com 146,0 t (3,40%). A captura por esforço de pesca foi medida em kg/dia por pescador, sendo observada uma diminuição de 7,53 kg/dia na captura, considerando-se todos os rios, quando comparados os anos 1994 a 1999. No rio Paranapanema, a produtividade média foi de 11,85 kg/dia; o rio Paraná apresentou uma variação cí­­clica da relação kg/dia a cada três anos (a ser confirmada nos próximos anos) e o rio Grande, com exceção de 1997, apresentou as maiores produtividades (kg/dia), quando em comparação aos outros rios, mas caracterizou se no perí­­odo estudado pelo constante decréscimo de produtividade até atingir uma perda de 41,20%. De uma forma geral, houve uma queda na produtividade dos rios estudados, sendo aconselhável a tomada de medidas de proteção da ictiofauna.

Napiórkowska-Krzebietke Agnieszka

Since 1967, the temperate, shallow, pond-type Lake Warniak has been subjected to different biomanipulation methods including the introduction of common carp, Cyprinus carpio L., grass carp, Ctenopharyngodon idella (Val.), silver carp, Hypophthalmichthys molitrix (Val.), and bighead carp, Hypophthalmichthys nobilis (Richardson) and then their removal in an effort to control macrophytes and phytoplankton. Recently, pilot stocking with predatory fish, particularly pike, Esox lucius L., has also been conducted. Hence, an examination of the long-term response patterns of phytoplankton to multiple fish-induced stressors was undertaken. In recent years, Chara domination (2000-2004) has helped to stabilize a clear-water state, high/good ecological status, and meso-eutrophic conditions. After the disappearance of Charales in 2004, the rapid, unstable changes in phytoplankton biomass, structure, and biodiversity suggested a shift toward a turbid-water state. As a result, the phytoplankton assemblages changed from those dominated by cryptophytes Y+X2+X1+LO (2000-2004) through those dominated by cyanobacteria K (2005-2008), dinoflagellates LO+Y (2009-2011), and cryptophytes Y+LO+F+X2 (2012), to those dominated by diatoms D+K+P+A (2013-2014) with representative taxa that occur in nutrient-rich and/or nutrient-poor water bodies. The 1967-2014 changes indicated that four periods, two with clear-water state and two with turbid-water state, alternately, one after the other, resulted from different fish pressure. Higher autochthonous fish biomass was usually accompanied by lower phytoplankton biomass. In contrast, the introduction of Cyprinidae fish had a stimulating effect on summer phytoplankton dominated by cyanobateria. Among the nutrients, only phosphorus played an important role.

Asfaruddin Asfaruddin, Farida Aryani

This study aims to find out the character of agronomy in some local chili varieties Kepahyang district. This research was conducted in Tugurejo village, Kabawetan sub – district, Kepahyang district, Bengkulu province. Research fields used include the plateau. The materials used are local scads kepahyang (wulung varieties, Aceh varieties, pendek varieties), manure, organic liquid fertilizer, chemical fertilizers. Tools used are house, handsprayerm sickle, bucket, ajir, mulch, meter, traypoot, ultra violet plastic and stationery. The resparch design used was a Randomized Block Design (RBD) with two factor, the first factor consists of three typus of processed fertilizer, namely liquid organic fertilizer (P1), manure (P2), chemical fertilizer (P3), while the second factor is local varieties, namely wulung (VI). Aceh varieties (V2), pendek varieties (V3). Each treatment was repeated three times. Observed variable were. Plant height, number of harvest crops, fruit diameter, fruit length, total fruit weight, fruit dry weight, flowering age, harvest age. The highest plant height is the manure treatment, significantly different from the treatment of liquid organic fertilizer and chemical fertilizer. The largest a mount of fruit cultivation is wulung varieties treatment, significantly different from the treatment of pendek varieties and aceh varieties. Fruit diameter and fruit length is the best treatment of aceh varieties, significantly different from the treatment of pendek varieties and wulung varieties.

Muddula Krishna Naranji, Govinda Rao Velamala, Sujatha Knadula

Based on two specimens of the flasher scorpionfish, species of Scorpaenopsis macrochir Ogilby, 1910 (85-96 mm, TL) collected from the Visakhapatnam coastal waters, India, we described S. macrochir as the new record from Indian waters. This species is characterized by having 12 dorsal spines, medial surface of pectoral fins with a black subterminal band along entire margin of fin; supraorbital spine ending in a single spinous point and unserrated ocular spines. Nasal spines usually divided into two to six small points. The present study describes full description of the species with illustration.

Mst. Rubia Banu, Siti Shapor Siraj, Annie Christianus et al.

This article has been retracted at the request of the Authors.The article is a duplicate of a paper that has already been published in Iranian Journal of Fisheries Sciences 2016; 15 (2) :738–750 here: http://www.jifro.ir/article-1-2213-en.html.One of the conditions of submission of a paper for publication is that authors declare explicitly that the paper is not under consideration for publication elsewhere. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Miguel Mancini, Fernanda Biolé, Luciana Cibils

Número con los trabajos presentados en el VII Congreso de Ecología y Manejo de Ecosistemas Acuáticos Pampeanos (EMEAP 7), 19 y 20 de septiembre de 2013 organizado por las cátedras de Acuicultura y Ecología de la Facultad de Agronomía y Veterinaria de la Universidad Nacional de Río Cuarto (Argentina). Los ecosistemas acuáticos, en especial los de la región pampeana, brindan múltiples funciones que muchas veces no son valoradas por la sociedad. Sin embargo, una gran cantidad de investigadores realizan a diario estudios de diferente naturaleza cuyos resultados deben ser puestos a consideración de los gestores para lograr un manejo integral de los ambientes y sus recursos. El presente volumen de la revista Biología Acuática incluye un total de veintisiete artículos que tratan diferentes disciplinas de la Ciencias Biológicas y de la Ecología. Esta cantidad de trabajos publicados refleja la necesidad de los profesionales del área de volcar los resultados de sus estudios e investigaciones en una revista de ámbito nacional. Los editores de este número son Miguel Mancini, Fernanda Biolé y Luciana Cibils.

S.K. Ghosh, B. Ghosh, P. Chakrabarti

Background. The omnivorous freshwater loach, Lepidocephalichthys guntea (Hamilton, 1822)inhibiting unique ecological niche where oxygen content is low. Its alimentary canal is remarkably short, which is surprising considering the fact that this fish is an omnivore. This peculiarity can be correlated with the specific nature of food. Therefore, the aim of the present study was to investigate the mucosal adaptation of the intestine in adult L. guntea with respective digestive- as well as respiratory function. Materials and methods. The surface design of the mucosa of different sections (anterior, mid, and posterior) of the intestine of L. guntea were studied using light and scanning electron microscope following commonly accepted procedures. Results. The mucosa of the anterior intestine was provided with various types of mucosal folds and crowded with almost closely oval or rounded columnar epithelial cells with prominent microridges. The irregular mucosal surface of the mid intestine was exemplified by regularly spaced columnar epithelial cells with minute and prominent microridges/microvilli. On the contrary, irregular mucosal folds with stumpy villi were detected in the posterior intestine. The mucosal surface of that region was made up of columnar epithelial cells containing inconspicuous microridges. In that region the submucosa was provided with increasing number of blood vessels. Various cellular elements in the anterior and mid intestine were accordingly adapted to serve the important functions of absorption and gas exchange. However, the arrangement of low mucosal folds and dense blood capillaries in between the folds in the posterior intestine unequivocally suggested its respiratory role. Conclusion. The micro-architectural pattern and cellular architecture of the anterior intestine and middle intestine of L. guntea unequivocally suggests that these two regions are adapted to serve major role of digestion and absorption process. However, major changes that appear in the posterior intestine are considerably reduction of the absorptive area and the penetration of blood capillaries in between the columnar epithelial cells. Therefore, the posterior intestine of L. guntea is probably adapted to suit its role for aerial respiration. However, further investigation is needed the detailed physiological processes involved for aerial respiration in the region concerned.

A.J. Almeida, M. Biscoito, J.I. Santana et al.

Following a series of surveys with bottom longlines and fish traps along the island slopes off the archipelagos of Madeira, Canaries and Cape Verde, and with bottom trawls along the coast of Morocco and Western Sahara between 2004 and 2006 many specimens of Synaphobranchus were caught, revealing the presence of two species. Based on these specimens and Museum preserved specimens from this areagrey cutthroat,Synaphobranchus affinis G&amp;uuml;nther, 1877, is recorded for the first time from off Portugal, Madeira archipelago, Great Meteor Seamount, Canary Islands, Morocco, Western Sahara, Cape Verde Islands, and Senegal. It is confirmed that S. kaupii is also conspecific in this area. Meristic and morphometric data of the specimens studied are also presented.

J.M. PEREZ

La revue INRA Productions Animales a 20 ans. En février 1988 paraissait en effet le premier numéro de la revue. Une aventure collective, retracée dans le premier article1 de ce numéro, à laquelle beaucoup de personnes ont participé : directeurs et rédacteurs en chef successifs de la revue, responsables de l’édition, membres du comité de rédaction, auteurs bien sûr, sans oublier les referees spécialisés (60 par an) garants de la qualité scientifique des articles. A l’occasion de ce 20ème anniversaire, qu’ils soient tous ici chaleureusement remerciés. «La forme, c’est le fond qui remonte à la surface» disait Victor Hugo. Dès sa création, la revue affiche l’ambition d’allier rigueur de l’information scientifique et exigence de l’écriture. Diffuser les résultats de la recherche même les plus pointus dans un langage accessible pour mieux faire connaître les travaux de l’INRA. Tel était notre objectif de départ. Cent numéros et 800 articles plus tard, à vous de nous dire si nous l’avons pleinement atteint. Mais soyons francs, et n’en déplaise à un autre écrivain célèbre2, nous ne souhaitons pas qu’un lecteur sur quatre soit mécontent pour poursuivre notre tâche éditoriale ! À quoi sert un anniversaire ? À affirmer son identité, sans doute. À retrouver également son passé pour mieux comprendre le présent et se projeter dans le futur, sûrement. À l’occasion de ce 20 anniversaire, la Rédaction a décidé de publier un numéro spécial sur «20 ans de recherches en productions animales à l’INRA». Le but : présenter, en s’appuyant sur quelques exemples marquants, les avancées scientifiques majeures issues des travaux de l’INRA ayant eu un impact en élevage au cours des deux dernières décennies et tracer des perspectives de recherches pour l’avenir. Le sommaire de ce numéro spécial est le fruit d’une réflexion commune entre les Directeurs scientifiques3 du secteur «Animal et Produits Animaux» de l’INRA, les Chefs de Département4 concernés et la Rédaction de la revue. Nul doute que ce numéro fera date dans l’histoire d’INRA Productions Animales. Bonne lecture à tous ! 1 J.M. Perez, M.-H. Farce, D. Caste. La revue INRA Productions animales a 20 ans, p 5-10. 2 Charles Péguy : «Une revue n’est vivante que si elle mécontente chaque fois un bon cinquième de ses abonnés». 3 Bernard Charley et Patrick Herpin. 4 Philippe Chemineau, Didier Boichard, Jean-Marc Meynard et Gilles Aumont.

María Laura Mendoza

Corallinales (Rhodophyta) in Tierra del Fuego are abundant, with 9 genera, 17 species and 1 subspecies. Pseudolithophyllum with 1 species (P. fueguianum), which represents 35.8% of the coralline algae, is dominant. The genera Parahydrolithon with 4 species (P. consociatum, P. discoideum, P. falklandicum, P. subantarcticum) and 20%, Lithothamnion with 3 species (Lt. heterocladum, Lt. rugosum, Lt. granuliferum) and 17.5%, and Synarthrophyton with 3 species (S. neglectum, S. patena, S. schmitzii) and 12% share are abundant. Clathromorphum with 4 species (Cl. annulatum, Cl. lemoineanum, Cl. obtectulum, Cl. Variabile) and a share of 5.8%, and Mesophyllum with 1 species (M. fueguianum) and a share of 4.9% are frequent. The remaining three genera, Bossiella with 1 subspecies (B. orbigniana ssp. orbigniana), Corallina with 2 species (C. elongata, C. officinalis) (1.1%), and Titanoderna with 1 species (T. conspectum) (1%) are scarce. C. officinalis is a cosmopolitan, and the other geniculate corallines are found in both hemispheres, whereas the crustose coralline occur only in the southern hemisphere. The characteristic vertical distribution of the species in the intertidal and subtidal zone of Tierra del Fuego is given. The Corallinales in the Antarctic Region are poorly known and need further investigation.

Vlasta Bartulovic, Davor Lucic, Alexis Conides et al.

The feeding habits of sand smelt, Atherina boyeri Risso, 1810 in the mouth of the Mala Neretva River were studied by examining the stomach contents of 1236 fishes collected from March 2001 to February 2002. Thirteen different food categories were identified. The greatest diversity was recorded in winter, especially in January, when 11 categories were present. The minimum (4) was in September, and was associated with the highest number of empty stomachs. Marine and estuarine species represented the bulk of the prey, while typically fresh-water species (Daphnia spp. and Cyclops spp.) were found only sporadically. Crustaceans were the most common prey and, of these, the most common were copepods (45%), followed by gammarid amphipods (34%), cladocerans (13%), decapod larvae (12%) and mysids (8%). Insects represented 7%. The percentage number of prey showed high seasonal variations. Copepods dominated in autumn and winter, cyclopoids in April, poecilostomatoids and harpacticoids in December, and calanoids in January and February. Decapod larvae dominated in March-May, and mysids in July-August. PCA and clustering analysis was performed on the prey data in order to reveal associations between prey items or seasonal similarities. The opportunistic mode of feeding of the species Atherina boyeri is also discussed.