Estudio biologíco pesquero del camaron Artemesia longinaris Bate de Mar del Plata

This consisted on the examination of approximately 31.000 specimens obtained from the commercial fishery in the region of Mar del Plata, between Cabo Corrientes and Punta Mogotes (Fig.3) and some complementary material of this area and its vicinities was also included. Living adult animals were also obtained and larvae and postlarvae of this species were separated from the plakton collected during several trips carried on by boats of coastal fleet. These trips allowed the study of the conditions of catches, and the selectivity of both net and fisherman. The aims of this work were to study the migrations, growth, sexual cycle, nutrition, behaviour, mortality and fishing of this important crustacean of commercial interest

Los crustáceos decápodos Brachyura del litoral bonaerense (R.Argentina)

In this work the taxonomy of the Brachyura Decapod Crustacea from fthe shelfwaters of the Province of Buenos Aires, Argentina (South Atlantic Ocean) is described, with particular reference to the biology and zoogeography. The material and methods are described and various zoogeographical problems are considered. A total of 25 species were encountered, and each one is briefly described together with its ecological and biological data. In many cases the geographical distribution has been extgended. Keys are given for the identification of the more common Brachyura from Argentina, as also for the sub-divisions of the Brachyura, including ffamilies, subfamilies and genera. The so-called "cangrejal" community (community composed of semiaquatic crabs) of the river Salado was studied, which was composed of Chasmagnathus granulata crabs. The species Uca uruguayensis formed the outer limit of the "cangrejal" community

Desarrollo larval de dos especies de Crustáceos Decápodos en el laboratorio, Pachycheles haigae Rodrigues Da Costa (Porcellanidae) y Chasmagnathus granulata Dana (Grapsidae)

The present paper is concerned with studies on the larval development of two species of crustacean Decapoda: Pachyceles haigae Rodrigues Da Costa, 1960 family Porcellanidae and Chasmagnathus granulata Dana, 1851, family Grapsidae. One preazoea, two zoeae with a total of five sub-stages, a and b, and the second zoea had sub-stages a, b and c. The greatest changes are observed in the transition from the first to the second zoea and from this to the megalopa. During the sub-stages, there occured minor changes, and a net moulting of the cuticle is not observed. The differences in these sub-stages are marked by changes in the number and shape of the appendages

Trophic niche partitioning of five skate species of genus Bathyraja in northern and central Patagonia, Argentina

Overexploitation of marine communities can lead to modifications in the structure of the food web and can force organisms like elasmobranchs to change their feeding habits. To evaluate the impact that fisheries have on food webs and on the interactions between species, it is necessary to describe and quantify the diet of the species involved and follow it through time. This study compares the diet of five skate species using the data obtained from the by-catch of the Argentine hake (Merluccius hubbsi) fishery in north and central Patagonia, Argentina. Diet composition was assessed by analysing the digestive tract contents and trophic overlapping between species of the genus Bathyraja: Bathyraja albomaculata, Bathyraja brachyurops, Bathyraja macloviana, Bathyraja magellanica and Bathyraja multispinis. A total of 184 stomachs were analysed. The diets of B. albomaculata and B. macloviana mainly comprised annelids, whereas that of B. brachyurops primarily comprised fish, including hake heads discarded by the fishery. The diets of B. magellanica and B. multispinis were largely based on crustaceans. Despite the morphological similarities and their shared preference for benthic habitats, no complete diet overlaps were found between the different species. These results suggest that these skate species have undergone a process of diet specialisation. This is a common feeding strategy that occurs to successfully eliminate competition when resources are limited, which corresponds to the conditions found in an environment being affected by the pressures of overfishing.Fil: Tschopp, Ayelen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Cristiani, Franco. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; ArgentinaFil: Garcia, Nestor Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; ArgentinaFil: Coscarella, Mariano Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales y Ciencias de la Salud - Sede Puerto Madryn. Departamento de Biología y Ambiente; Argentin

Argentine pearl fish : A complete study of the Argentine pearl fish, Cynolebias bellottii

Etymology Cynolebias: Lebias: with dog-like teeth; bellottii: in honor of Dr. Bellotti, who obtained the species. Taxonomy Class: Teleostomi Order: Cyprinodontiformes Sub-Order: Cyprinodontidei Family: Cyprinodontidae Genus: Cynolebias Steindachner Species: Cynolebias bellottii SteindachnerFacultad de Ciencias Naturales y Muse

Descripción de la morfología externa e interna del langostino con algunas aplicaciones de indole taxonómica y biológica

In the present paper the external and internal morphology of the shrimp Pleoticus muelleri (Bate), is described in detail. Special attention is given to those features which are of diagnostic value or which are significant for a fuller understanding of the biology of this species. The major portion of the paper deals with the description of the cephalopereion, pleon and telson and its appendages, as well as the nervous, respiratory, circulatory, digestive, excretory and reproductive systems. Special attention is given to the digestive system, the stomodaeal apparatus and sexual dimorphism. The relations between form and function of several organs and systems are pointed out. A study is made of the development of the gonads, the sexual cycle in males and females; the variations found in relative weight and size are described. The phylogenetical jposition of the Penaeidae, the genera of the subfamily Solenoceridae and of P. muelleri are discussed. (PDF contains 72 pages

Sobre la distribución de los crustáceos decápodos de la provincia biogeográfica Magallánica y la región Antártica

The distribution of decapod crustaceans in the southernmost areas of South America and the Antarctic is assessed considering the Magellan Biogeographic Province instead of the antiboreal region. Possible associations between decapod crustaceans from the Magellan Biogeographic Province and those from the Antarctic region are analysed. Species records were assigned to seven geographic regions that were clustered using multivariate analyses based on species presence/absence and Bray-Curtis similarity. The results showed two well-established clusters, one of which included the Pacific and Atlantic areas of the Magellan Province, the southern tip of South America and the Kerguelen Arc islands, with the highest similarity between the southern tip and the Atlantic area. Another cluster was well separated and included the Antarctic and South Georgia with the highest similarity index. Earlier studies and results obtained here suggest that the faunas of southern Chile and southern Argentina are biogeographically related. There is a low level of association among decapod species from the circum-Antarctic region and the Magellan Province.Se estudió la distribución de los crustáceos decápodos en las áreas más australes de Sudamérica, considerando la Provincia Biogeográfica Magallánica en lugar de la región antiboreal. Se analizó la posible asociación entre los crustáceos de la Provincia Magallánica y los de la región antártica. Las especies registradas fueron asignadas a siete regiones geográficas, las que fueron agrupadas utilizando análisis de agrupamientos basado en presencia/ausencia de especies. Se utilizó el índice de similitud de Bray- Curtis. Los resultados mostraron dos grupos bien definidos de los cuales uno incluyó las áreas pacífica y atlántica de la Provincia Magallánica, la del extremo más austral de Sudamérica y las islas del Arco de Kerguelen. El otro grupo estuvo separado del anterior e incluyó la Antártida y las Islas Georgias con el índice de similitud más alto. Estudios anteriores y los resultados obtenidos en éste, sugieren que las faunas del sur de Chile y sur de Argentina se encuentran relacionadas. Existe baja asociación entre las especies actuales de crustáceos decápodos con distribución circumantártica y las de la Provincia Magallánica

Areas de migración y ecología de la anchoa Lycengraulis olidus (Günther) en las aguas argentinas (Pisces, fam. Engraulidae)

The purpose of the present study was to confirm the migratory habits of the anchovy, Lycengraulis olidus (Günther), between fresh and sea water environments. Anchovies were examined from three freshwater localities: Bella Vista and Rosario (Paraná river) and Punta Lara (La Plata river), and from four marine localities; Mar del Plata, Bahia Blanca, San Blas and Patagones, all in the Argentine Republic. Five meristic and nine morphometric characters were selected for study, namely: vertebrae; dorsal, pectoral and anal fin rays; gill rakers on the first gill arch; head-length; body-depth; distance between the snout and dorsal, pectoral, ventral and anal fin; eye-diameter; snout and maxilary. The food of the anchovy in fresh and sea water consists principally of fish and crustaceans including copepods, paleamonids, sergestids and larvae of Brachyura. The condition factor of the anchovy was lower in the fresh-water samples and higher in the marine samples. (PDF has 32 pages (two pages on each

Nuevos datos sobre la biología de la especie <i>Anchoa marinii</i> Hildebrand de Mar del Plata

Un grupo principal de la fauna íctíca del Mar Argentino lo constituyen los engráulidos que se destacan no sólo por su importancia en la economía pesquera del país, sino también por la complejidad de los problemas taxonómicos y ecológicos de las especies, a lo cual se agrega su extensa distribución geográfica. Por tal motivo se hizo imperiosa la revisión sistemática de las especies que pueblan las aguas marinas y continentales de la República Argentina y el conocimiento más exacto de su ciclo vital. Con esta finalidad se presentaron en una publicación anterior (Fuster de Plaza y Boschi, 1958), los primeros resultados de las investigaciones de la anchoíta (Engraulis anchoita) de la zona de Mar del Plata, y con el mismo propósito seguirán otras contribuciones acerca de la biología y ecología de las especies con hábitos migratorios entre los ambientes marinos y dulceacuícolas [Lyncengraulis olidus (Günther)].Trabajo publicado en Actas y trabajos del Primer Congreso Sudamericano de Zoología, tomo IV, Universidad Nacional de La Plata, 1960.Facultad de Ciencias Naturales y Muse

Nuevos datos sobre la biología de la especie <i>Anchoa marinii</i> Hildebrand de Mar del Plata

Un grupo principal de la fauna íctíca del Mar Argentino lo constituyen los engráulidos que se destacan no sólo por su importancia en la economía pesquera del país, sino también por la complejidad de los problemas taxonómicos y ecológicos de las especies, a lo cual se agrega su extensa distribución geográfica. Por tal motivo se hizo imperiosa la revisión sistemática de las especies que pueblan las aguas marinas y continentales de la República Argentina y el conocimiento más exacto de su ciclo vital. Con esta finalidad se presentaron en una publicación anterior (Fuster de Plaza y Boschi, 1958), los primeros resultados de las investigaciones de la anchoíta (Engraulis anchoita) de la zona de Mar del Plata, y con el mismo propósito seguirán otras contribuciones acerca de la biología y ecología de las especies con hábitos migratorios entre los ambientes marinos y dulceacuícolas [Lyncengraulis olidus (Günther)].Trabajo publicado en Actas y trabajos del Primer Congreso Sudamericano de Zoología, tomo IV, Universidad Nacional de La Plata, 1960.Facultad de Ciencias Naturales y Muse