摘要:

A new curimatid fish,Curimata gnaca, from two localities, both in the neighborhoods of Resistencia, Chaco Province, Argentine, is described. The species is distinguished from other curimatids by the position of the mouth, a low number of perforated scales in lateral line, scales with straight margin on sides of body and long pectoral fins. The new species is placed in the genusCurimatauntil the problems within it will be solved.

ISSN:0165-0521    

DOI:10.1080/01650528809360753

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A detailed comparative study of the diet of wild brown and rainbow trout in the Ramos Mexía reservoir, Neuquén Province, during 1982 and 1983 was made. The seasonal composition of both diets was determined, calculating number, volume, and occurrence. The feeding habits of the brown trout are based mainly on perch, silverside, galaxiids, molluscs, and crustaceans; for rainbow trout, galaxiids, terrestrial insects, ostracods, crustaceans, and molluscs were recorded. Fishes were mainly caught throughout the year by brown trouts, while rainbow trouts capture mostly ostracods during spring and galaxiids throughout the rest of the year. A decrease in the percentage of galaxiids, insects, and molluscs was observed with the increase of brown trout size, while increasing that of silverside. Rainbow trouts also showed an increase in perch and galaxiids predation with size, with a decrease in crustaceans and insects. A diet overlap was recorded only in spring. Trouts occupy both the 3rd and 5th level in the trophic chain, being very active ichthyofagous predators.

ISSN:0165-0521    

DOI:10.1080/01650528809360754

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

STAWIKOWSKI, R. & U. WERNER (1988): Die Buntbarsche der Neuen Welt ‐Südamerika. Edition Kernen in Eugen Ulmer Publ., Stuttgart. 288 pp, 180 colour photos and 50 in black‐and‐white, hardcover, DM 45.00.

ISSN:0165-0521    

DOI:10.1080/01650528809360761

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The seasonal distribution and food habits of the Spectacled Bear,Tremarctos ornatus, were studied in the subalpine paramo of the Antisana volcano, in Ecuador. The location and age of bear signs indicated that bears occupy paramo areas seasonally up to a maximum of 4,000 m from February to July. Feeding evidence and scat analysis confirmed that bromeliads(Puyasp.) are important bear's food in the highlands. Because the importance of paramo and montane forest habitats to the spectacled bear, large, contiguous areas of these ecotypes need to be preserved.

ISSN:0165-0521    

DOI:10.1080/01650528809360755

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Heteromeyenia horstiKilian, was found in the Mascardi lake, Río Negro Province, Argentina. The taxonomic study was made on the comparative analysis of the microscleres, because the sponges had no gemmules. The present one is the southernmost place for argentinian freshwater sponges. The analysis of the material from different ponds of Corrientes Province (Argentina), allows to extend the geographical distribution ofHeteromeyenia baileyi(Bowerbank). Thus,HeteromeyeniaPotts is represented by three species in Argentina:H. stepanowi(Dybowsky, 1884),H. baileyi(Bowerbank, 1863), andH. horstiKilian, 1976.

ISSN:0165-0521    

DOI:10.1080/01650528809360756

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

During a period of high water level, samples of Zooplankton from the main course of Paraná river, side‐arms and tributaries were obtained (25 sampling stations). The main course, characterized by high discharge and current velocity of water, showed a small number of species, most of them planktonic, and a low abundance of organisms (X: 10 720 ind m3). The side‐arms and tributaries showed lower discharge and current velocity, together with both a higher number of species and abundance (X: 15 190 and 320 435 ind m3, respectively).

ISSN:0165-0521    

DOI:10.1080/01650528809360757

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Fish populations of water bodies of the lower Paraguay River at Formosa area (26° 10´S ‐ 58° 10´W) sampled during 1971 are studied. Qualitative and quantitative structure of fish communities, as well as dominance and occurrence, and size of fishes are analysed. Some limnological parameters, such as surface area, depth, and plant cover of the lagoons are included. Comparisons are made between the fish fauna present in these water bodies and those caught in other ones of similar characteristics located in the middle Paraná River.

ISSN:0165-0521    

DOI:10.1080/01650528809360758

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The age and growth ofAstyanax eigenmanniorumfrom San Roque Lake (Province of Córdoba, Argentina) were studied. During two years, 3,086 specimens were analysed; these were collected monthly by means of a dragging net. Lepidologic studies were made to determine age and growth.

ISSN:0165-0521    

DOI:10.1080/01650528809360759

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Growth patterns are compared in the trematodeProctoeces humboldtiGeorge‐Nascimento & Quiroga, 1983 (Fellodistomidae), parasite of the gonads of the molluscsFissurella crassaLamarck, 1822 andFissurella latimarginataSowerby, 1835 andProctoeces chilensisOliva, 1984, parasite of the intestine of the fishSicyases sanguineusMüller & Tronschel, 1843 (Gobiesocidae). The flukes reach sexual maturity in both, the vertebrate and invertebrate host. The average size of the body parts and organs, and patterns of allometric growth, are influenced by the host species; moreover, the coefficient of variability of the body parts and organs studied is also affected. In the light of our results, and those of Bray & Gibson (1980), only two species are to be considered as valid in the genusProctoeces, namelyP. maculatus(Looss, 1907) andP. lintoniSiddiqi & Cable, 1960. Thus,P. humboldtiandP. chilensisbecome synonyms ofP. lintoni, because the structure of the seminal vesicles is identical. The presence of mature worms in vertebrate and invertebrate hosts is explained according to the hypothetical sequence of life cycles in digenetic trematodes (Rohde, 1973).

ISSN:0165-0521    

DOI:10.1080/01650528809360760

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0165-0521    

DOI:10.1080/01650528809360752

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor