Gillnet selectivity in the capture of barred sorubim Pseudoplatystoma fasciatum in the middle Orinoco basin. Zootecnia Trop. ISSN An indirect method of the comparison of the captures of Pseudoplatystoma fasciatum by nets of 10 cm of mesh opening with the captures with nets of 7 cm of opening was used to study the selectivity, being used fish captured with nets of 10 cm opening 30 - 84 cm total length and 76 fish captured with nets of 7 cm opening 28 - 51 cm of total length in a lagoon flood of the middle Orinoco during the dry season.
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Correos No. Recibido: 17 de noviembre de Aceptado: 8 de mayo de The gafftopsail catfish Bagre marinus is one of the species of most importance to fisheries in the Gulf of Mexico, particularly in the coastal region of Tabasco State, where it is captured abundantly almost all year round in shallow coastal zones.
Although, there is neither ecological nor biological information about this species in the coastal zone of Tabasco State. This study aims to describe the feeding habits of gafftopsail catfish.
Seasonal changes in the diet and its relation with reproductive period will also be discussed. Analyzes of stomachs contents of individuals 97 females and 68 males for dry season, females and 38 males for rainy season and 83 females and 44 males for nortes season obtained from two commercial landings located in the Chiltepec municipality, Paraiso, Tabasco along one year May to April Brachyurans were the more important preys inside the annual diet of species, reached a maximum frequency of occurrence during dry season Few seasonal changes in diet of both sexes were observed, with a progressive increase of occurrence of fishes and diminution of stomatopods and penaeid shrimps.
No significant differences were finding in total diet between females and males. The variation of the proportion of fullness stomachs and fullness weight index along the year can be related with the reproductive behavior of species. No se observaron diferencias significativas entre las dietas totales de hembras y machos. In the Gulf of Mexico, three species of this family are common: Ariopsis felis L.
Along the southeast coastal zone of the Gulf of Mexico, gafftopsail catfish B. A low variation in landing volume was observed for this species in Tabasco State throughout the 's , with an average volume of tons. The great abundance of these ariids in coastal marine ecosystems of the Gulf of Mexico Sheridan et al.
Despite the aforementioned aspects high economical and ecological importance , there is neither ecological nor biological information about this species in the coastal zone of Tabasco State, the present study being the first scientific report to deal with the subject.
Fishery area is a coastal zone in front of the Chiltepec Barrier Figure 1. The commonest catch method employed to capture this species was the bottom long line set at depths of 10 to 40m. Randomized sampling of fishes was done. Each fish was measured standard and total length to the nearest mm, weighted total and somatic weight to the nearest g and sex was identified. The total number of individuals sampled was , divided in: 97 females and 68 males in the dry season, females and 38 males in the rainy season and 83 females and 44 males in the nortes season.
Standard length for females varied between and mm and for males between and mm. The stomach contents were examined. Each item was identified to the lowest possible taxon, counted and weighed wet weight to the nearest 0. The proportion of stomach fullness stomachs with food was expressed as a percentage. Fullness weight index was expressed as a percentage, dividing the total wet weight of the food items by the somatic weight of the fish.
An arcsine transformation of the original data was applied Zar, The diet of the gafftopsail catfish consisted of 30 identified prey species. These species were included in five groups: stomatopoda three species , penaeidae six species , brachyura six species , actinopterygii six species and "other groups" nine species. The last group included several species that occurred at low densities and sparsely throughout the year; consequently this prey group was not included in the statistical comparisons.
Only two genus of prey were found during the three seasons in both females and males stomach contents; these were: Squilla sp and Callinectes sp, mostly S.
The presence of other prey species was not constant throughout the year Table 1. The Kendall concordance coefficient shows that the three indices provide similar information about the diet of males and females during the dry and rainy season. As it was considered that the three indices provide very similar information, the percentage of frequency occurrence was chosen for description and statistical comparisons of the diet of each sex.
In general, the brachyurans were the most important prey in the diet of both sexes in all seasons. In females its maximum frequency of occurrence In males the brachyurans reached their maximum frequency of occurrence In females the diminution of the frequency of occurrence of the stomatopoda group was notorious from the dry Despite these changes in individual prey groups, the results of the total diet comparison suggest that the diet of females of gafftopsail catfish does not change significantly in different seasons Table 1.
In males a similar pattern was found, stomatopods presented a progressive diminution in occurrence, the principal variation was between the rainy Penaeid shrimps were only present in dry season. No significant differences were found in total diet between females and males of gafftopsail catfish throughout the seasons.
The proportion of stomach fullness showed a similar tendency in females and males. The maximum values for females The minimum proportion of stomach fullness for females In the case of the fullness weight index, the maximum value for females 2. For males the maximum value for the fullness weight index 2. No significant differences between sexes and interaction between months and sex were detected Table 2.
The high and constant presence of crustaceans, mainly brachyurans, throughout the seasons characterizes the diet of gafftopsail catfish. Presence of fishes was constant too, however with lesser importance. The situation above can be related to a constant availability of prey, however, without quantitative data about prey abundance, the above assumption remains speculative. On the other hand, the disappearance or decrease of prey in males in the rainy season and in both sexes in the nortes season, is more related to a reduction in full stomachs number than to a real variation in diet.
Relative lack of variation of diet in different seasons was observed in other species of catfishes such as C. Mol, Differences in diet composition between males and females were not observed, but differences between sexes were clear when the percentage of fullness stomachs and the fullness weight index were analyzed. Despite this decrease in fullness weight index, the number of stomachs with food were high.
In males it could be observed that during the rainy season in September and October a decrease in the number of individuals captured and fullness stomachs occurred.
A progressive increase in fullness weight index can be attributed to the recruitment of males that have already finished the period of oral incubation. The increment in the proportion of stomach fullness in both females and males during January probably indicates the end of the reproductive period.
Vieira and Ocean. Daniel Loebmann for their criticism of the manuscript and data analysis. Thanks for Biol. Diego Santiago and Ocean. Dennis Helebrandt for revision the English manuscript. Additional comments and suggestions by two anonymous reviewers significantly improved the final version. Ariidae en el Golfo de Cariaco, Venezuela.
Scientia Marina 54, A critical review of methods of studying fish feeding based on analysis of stomach contents: application to elasmobranchs fishes. Canadian Journal of Fisheries and Aquatic Sciences 54, CROW, M. Some statistical techniques for analyzing the stomach contents of fish. Caillet, G. The ecology of fish communities in the Mississippi River deltaic plain. En: Fish community ecology in estuaries and coastal lagoons: towards an ecosystem integration.
Optimal foraging theory in the marine context. Oceanography and Marine Biology Annual Review 18, Stomach contents analysis: a review of methods and their application. Journal of Fish Biology 17, MOL, J. Ontogenetic diet shifts and diet overlap among three closely related neotropical armoured catfishes. Journal of Fish Biology 47, Algunos aspectos reproductivos del bagre rayado, Pseudoplatystoma fasciatum Linnaeus, Pisces: Pimelodidae en la Laguna Grande, Maturin, Venezuela.
Ciencias Marinas 24, Reproduction and food habits of seven species of northern Gulf of Mexico fishes. Contributions in Marine Science 27, In: FAO species identification sheets for fisheries purposes. Western Central Atlantic fishing area Fisher, W. The food and feeding of two co-occurring marine catfish Galeichthys feliceps and G.
Experiments in ecology-Their logical design and interpretation using analysis of variance. Cambridge: Cambridge University Press. VEGA, E. Instituto de Ciencias del Mar y Limnologia. Ecology of three sea catfishes Ariidae in a tropical coastal ecosystem - Southern Gulf of Mexico. Marine Ecology Progress Series 49, ZAR, J. Biostatistical analysis.
Caracterización morfométrica del bagre rayado para la cuenca del Magdalena
A Colombia. Received: February 15; Accepted: October The objective of this study was to evaluate three internal cryoprotectants to preserve semen of striped catfish Pseudoplatystoma magdaleniatum. The semen was diluted in the cryoprotective solution 1: 3 in 2. A 3x2 factorial design was used, and the control treatment was fresh semen SF.
Rio Magdalena Striped Bagre
Fish, sea food and fish products. Donate Join us. Search Search for:. Bagre Rayado del Magdalena In translation, spanish version online Hai imparato qualcosa di nuovo da questa pagina?
Important User Information: Remote access to EBSCO's databases is permitted to patrons of subscribing institutions accessing from remote locations for personal, non-commercial use. However, remote access to EBSCO's databases from non-subscribing institutions is not allowed if the purpose of the use is for commercial gain through cost reduction or avoidance for a non-subscribing institution. Source: Archivos de Medicina Veterinaria. Abstract: The aim was to determine the effect of different extenders and freezing rates on bagre rayado seminal quality. Sexually mature males 1.
The common name sorubim is used for several similarly shaped species in the genus. Body markings, typical habitat and maximum size differ. The Sorubim is distinguished by its flattened head, elongate body and large terminal mouth. Its silvery gray upper body with heiroglyphic markings dorsally, and tiger stripes laterally, also set it apart. The silver gray on its dorsum changes abruptly to white on its ventral sides, as well as its abdomen. Specimens up to one meter in length and more than pounds have been reported.