The marine fishes of Panama. Part I

Abstract

Atlantic coast, the canal is provided with locks, consisting of three flights of 15 feet each. Beyond the locks lies Lake Gatun, a large, artificial body of fresh water, made by the construction of a very large dam across the Rio Chagres and part of its valley. This lake is approximately 45 feet above sea level and it extends partly as a broadly expanded body of water and partly confined to the channel of the canal from Gatun to Pedro Miguel, a distance of about 30 miles. Locks with a single flight of 15 feet occur at Pedro Miguel, and below these locks lies another fresh water lake which contains about 3 or 4 miles of the channel of the canal. Then at Miraflores are locks containing two flights of 15 feet each, which bring a ship passing through the canal from the Atlantic to the Pacific back to sea level.It is, therefore, evident that the Panama Canal provides no passageway from ocean to ocean for strictly marine fishes. However, it does not appear impossible for some of the marine forms which frequent brackish, or even fresh water, such as some of the Centropomida, Gerridce and Gobiida, to endure the fresh water and to find their way from ocean to ocean. THE COMMERCIAL FISHERIES OF PANAMA.Nearly all fishing on the coasts of Panama is done at night for two reasons; first, because it is quite generally believed that fish can see the nets during the day and that, therefore, larger catches can be made at night; and second, because the fish must be placed on the markets, which usually are open only in the forenoon, early and disposed of the same day in order to prevent decomposition, as recourse to icing is rarely taken.Both drag nets and set nets are used, and it is feared that altogether too frequently for the welfare of the fishery dynamite is employed; at least it was during the periods of our visits to Panama. Bamboo traps, such as are also used in the West Indies, are in general use, particularly on the Atlantic coast. The cast net is very common and at times quite successful. Hook and line fishing also is engaged in to a limited extent.Very few power boats are used, the sail or oar and paddle being depended upon. Most of the boats are of the "dugout" type, which are rather heavy and which capsize easily and must be quite carefully manipulated.Class II. Elasmobranchii.Order II. Asterospondyli.Family II. OrectolobidaB. THE NURSE SHARKS.Body short and subcylindrical to moderate and depressed ; nostrils with a nasoral groove and with a cirrus or barbel; mouth transverse, with labial folds around angles; teeth compressed, with or without lateral cusps on each side of the median one; eyes very small, without nictitating membrane; spiracle minute to large, and behind the eye or more or less below it; gill-slits small to medium, the posterior 2 or 3 above base of pectoral; caudal fin narrow, usually without exerted lower lobe ; other fins short and broad ; no fin spines ; no caudal pits.

Electrophoretic and Functional Enzymic Evolution in Four Species of Eastern Pacific Barracudas From Different Thermal Environments

“…Sphyraena ensis differs from the other species in having the pelvic fins attached below the tips of the pectoral fins (as opposed to attachment well behind the tips of the pectoral fins) and fewer scales in the lateral line series (105-120 versus 145-170 in the other species) (Meek and Hildebrand, 1923;Hildebrand, 1946;Lavenberg and Fitch, 1966;Miller and Lea, 1972).…”

Soft-bottom demersal ichthyofauna from the continental shelf off Jalisco and Colima, Mexico, during spring 1995

“…The basic literature was used for the general identification of the species, principally the works of Jordan and Evermann (I 896-1900) Meek andHildebrand (1923-1928) Miller and Lea (1972), Instituto National de la Pesca (1976), Castro-Aguirre (1978) Thomson et al (1979), Eschmeyer et al (I 983) and Allen and Robertson (1994). Specialized taxonomic keys were also used, such as those of Hubbs and Schultz (1939) for Batrachoididae, Norman (1934) for Pleuronectiformes, Hubbs (I 952) for Labrisomidae and Berry and Baldwin (1966) for Balistidae.…”

Revalidação de Cathorops arenatus e Cathorops agassizii (Siluriformes, Ariidae), bagres marinhos das regiões norte e nordeste da América do Sul

“…Fica demonstrado na presente análise que o menor número ou ausência de dentes molariformes na porção posterior do dentário, o menor tamanho das placas acessórias e a maior distância entre elas são diferenças relacionadas ao sexo, características dos machos de C. agassizii. Diferenças relacionadas ao sexo também foram empregadas por outros autores na determinação de espécies de Cathorops (CUVIER & VALENCIENNES, 1840, GÜNTHER, 1864e MEEK & HILDEBRAND, 1923. O erro poderia induzir à conclusão de que T. agassizii seria sinônimo júnior de C. spixii, por ter sido descrito com base em um caráter dimorfico, porém o exame do exemplar-tipo e a descrição de EIGENMANN & EIGENMANN (1888) permitem reconhecer outras características que não diferem com o sexo e permitem distinguir a espécie das demais designadas ao gênero Cathorops.…”