Cichla temensis

Abstract: Cichla temensis collected in Venezuela attained a mean standard length of 440 mm, and C. orinocensis and C. intermedia mean lengths of 309 and 321 mm, respectively. There was little evidence of size diVerences between sexes. Opaque zones on otoliths corresponded to the period of peak of reproductive activity and low fish body condition (K). When aggregated across sites, linear estimates for growth of fish >age I were 57·5, 27·6, and 19·6 mm year "1 for C. temensis, C. orinocensis, and C. intermedia, respectively. Fish from the Cinaruco River appeared to spawn at age I, and prior to first maturation had grown 25, 21, and 23 mm month "1 , respectively, for C. temensis, C. orinocensis ,a ndC. intermedia. There was little intersite variation in growth rates, and diVerences in sizes of conspecifics from diVerent sizes were due to age diVerences. Cichla in captivity spawn several times per year. The present results indicate that the annual cycle or tropical wet/dry seasonality promotes reproductive seasonality in Cichla. The energetic cost of reproduction and brood defence probably constrains most individuals to one spawn per year. Conversely, populations living in relatively aseasonal reservoir environments may have several spawns per year, in which case growth zones on hard structures are diYcult to interpret.

Abstract: This paper examines the life history and growth relationships of Cichla ocellaris, a predatory South American cichlid. Data from extensive field studies in Gatun Lake, Panama, where C. ocellaris was introduced, present a complete life history for this species from pair formation through parental care of the young. These data are relevant to fish management and culture efforts, since C. ocellaris is one of the few New World cichlid species which is exploited commercially. New interpretations of the evolution of parental care patterns in cichlids, and the possible significance of latitudinal differences in parental care patterns among guarders, are included. Creel surveys allow comparison of length/weight ratios from native habitats in Brazil and Venezuela, non-native lacustrine habitats in Panama' and Hawaii, and non-native riverine habitats in Panama. These results indicate that the potential for short-term harvest of cichlid production is higher in lake habitats, but for long-term continuous harvest, it is greater in rivers. Este trabajo trata sobre los estudios de los diferentes estadios de desarrollo y relaciones de crecimiento de Cichla ocellaris, un ciclido dulceacuicola suramericano introducido en el Lago Gatuin, Panama. Los estudios desarrollados incluyen desde el periodo de apareamiento hasta el desarrollo del adulto. El trabajo hace enfasis en: apareamiento, desove, cuidado paternal y mecanismos de defensa de los juveniles (coloracion y comportamiento). Se discute adem'as la evolucion del cuidado parental en neces. Los datos provenientes de las pesquerias no permitieron hacer comparaciones de las relaciones de talla/peso para diferentes habitats: nativos (Brazil y Venezuela); no nativos lacustrinos (Panam'a y Hawaii); no nativos fluviales (Panama'). Los resultados mostraron una alta produccion en periodos cortos para los lagos. Sin embargo, los rios mostraron una alta produccion en periodos largos. Esta conclusion permitira dirigir mejor los esfuerzos que se haran para manejar y cultivar esta especie de alto valor comercial. THE CICHLIDAE, a family of secondary fishes (i.e., capable of tolerating seawater for at least a brief period of time), are largely indigenous to Central America, South America, and Africa. Their preferred habitat is lentic (slow-moving) waters, and of the approximately 1000 species in the family (Goldstein 1973), the vast majority are associated with lakes. For instance, in the Great Lakes of East Africa there are nearly 400 species, almost all endemic (Fryer and Iles 1972). A parallel New World example, although of much more recent origin (Myers 1966), is found in the Great Lakes of Nicaragua and their associated drainage basins which contain approximately 75 percent of the almost 100 Central American species, mostly of the genus Cichiasoma. In addition to the many lake forms there are also riverine cichlids, but these are generally considered more primitive, closer to the original stock from which the entire group has evolved (Regan 1906). A recognition of the preeminence of cichlids in lentic rather than lotic (fast-moving) aquatic environments is fundamental to an understanding of this family's ecology. Several characteristics may have enabled cichlids to exploit lentic habitats. Their fully enclosed (physoclistous) air bladder, in which the secretion of gases can maintain a constant bladder volume with depth, allows them to frequent relatively deep waters in lakes; for example, in Lake Tanganyika, cichlids dominate the deepest fish fauna in the littoral regions between 100-120 meters (Lowe-McConnell 1975). In addition, cichlids have fins and associated musculature ideally suited for accurate and finely controlled movements, including the ability to fan water. Fanning enables cichlids to rear young in oxygen-depleted lakes by providing a steady flow of water over the developing eggs, thus allowing them to be independent of river flow for spawning. Finally, well-developed oral incubation of young provides protection against egg and larval predators. The body form of cichlids bears a striking resemblance to such North American centrachids as the bluegill, crappies, sunfish, and bass species. Morphologically, the major distinctions between the two families are, first, that cichlids usually have an incompete lateral line on at least one side of their body, whereas centrarchids have complete lateral lines; second, cichlids have a single nostril at each side of the head, while centrarchids have a pair on each side, typical of percoid fishes. The ecological significance of these two morphological differences is unknown. While both Cichlidae and Centrarchidae are members of the same suborder Percoidei (with 144 BIOTROPICA 12(2): 144-157 1980 This content downloaded from 157.55.39.223 on Wed, 24 Aug 2016 04:14:03 UTC All use subject to http://about.jstor.org/terms about 60 families), parallel evolution in aquatic habitats may be more responsible for their similar morphology than any close taxonomic relationship. Cichlids derive their notoriety from two sources. First, as brightly colored fishes which adapt well and breed in aquarium tanks (i.e., lentic habitats), they are highly favored pets. Some delights of the fish fancier are the Jack Dempsey (Cichlasoma biocellatum), the discus (Symphysodon sp. ), the Oscar (Astronotus ocellatus), and the graceful angelfish (Pterophyllum sp.), all of South America. Second, one genus of African cichlid, still called by its common name "tilapia," has achieved a worldwide distribution because of its commercial importance. This species, formerly Tilapia mossambica, is now placed with all related mouthbrooders of this group in the genus Sarotherdon (see Trewavas 1973). Many species in this genus can be cultured easily in rearing ponds on a diet of relatively inexpensive food. Sarotherdon esculentus feeds on phytoplankton with fine gillrakers and a mucous secretion to trap the algae (Greenwood 1953). There is a considerable literature on the rearing of tilapia (Thys van de Audenaerde 1968), and the fish has been highly touted as a potential solution for the world protein shortage, although its development as an important food resource has not yet lived up to expectations. In Africa, a great number of cichlid species are commercially exploited on a large scale. For instance, in Lake Victoria the yearly catch of cichlids for consumption has been estimated at greater than 30,000 metric tons (Fryer and Iles 1972:387). In contrast, relatively few of the New World's approximately 200 species of cichlids find their way to markets in large numbers. The probable reasons for this disparity are 1), the dearth of large lakes in the New World; 2), the presence in Africa of European nationals who were able to adapt their expertise in marine fisheries management to African lakes; and 3), differences in local availability of alternative food resources. In addition, in the New World most of the aboriginal peoples have been exterminated or displaced by Europeans, over the past four centuries, and recent anthropological evidence (R. Cooke, pers. comm.) suggests that the former Indian populations relied considerably more on fishes as a regular part of their diet. Undoubtedly, all of these natural and historical factors have played a part in this striking difference between Old and New World exploitation of cichlids as food sources. One notable exception to this above generalization is the South American predatory cichlid Cichla ocellaris, whose fine taste and abundance in native habitats have made it an important commercial species. In Manaus, Brazil, this species is brought into local markets for sale by the thousands, and commands one of the highest prices. According to Meschkat's (1960) estimate, C. ocellaris is the most frequent cichlid sold commercially in Manaus, with a ranking of 17 among all freshwater fishes in total yearly catch. In addition, C. ocellaris is an excellent sport fish, and for this reason has been introduced to various water bodies throughout its native range and in other countries, including Hawaii (Devick 1969), Puerto Rico (Erdman 1972), and Panama. In Panama its presence has had measurable and dramatic effects on the local fish fauna (Zaret and Paine 1973). Cichla has also been successfully reared in Brazil in artificial ponds (Sawaya and Braga 1946, Braga 1952, Fontenele 1950), although these culturing activities appear to have lapsed. There are four species of the genus, all native to South America. These include: C. ocellaris and C. temensis, which are sympatric throughout the Amazon and Orinoco basin (Eigenmann and Allen 1942, Fowler 1954); C. intermedia, which so far has been ~~~~~~~~~~~~~~* v

Abstract: Lake Paranoa is a tropical reservoir for the City of Brasilia, which became eutrophic due to inadequate sewage treatment associated with intensive population growth. At present, two wastewater treatment plants are capable of processing up to 95% of the domestic sewage, thereby successfully reducing eutrophization. We evaluated both genotoxic and cytotoxic parameters in several fish species (Geophagus brasiliensis, Cichla temensis, Hoplias malabaricus, Astyanax bimaculatus lacustres, Oreochromis niloticus, Cyprinus carpio and Steindachnerina insculpita) by using the micronucleus (MN) test, the comet assay and nuclear abnormality assessment in peripheral erythrocytes. The highest frequencies of MN were found in Cichla temensis and Hoplias malabaricus, which were statistically significant when compared to the other species. However, Steindachnerina insculpita (a detritivorous and lake-floor feeder species) showed the highest index of DNA damage in the comet assay, followed by C. temensis (piscivorous). Nuclear abnormalities, such as binucleated, blebbed, lobed and notched cells, were used as evidence of cytotoxicity. Oreochromis niloticus followed by Hoplias malaricus, ominivorous/detritivotous and piscivorous species, respectively, presented the highest frequency of nuclear abnormalities, especially notched cells, while the herbivorous Astyanax bimaculatus lacustres showed the lowest frequency compared to the other species studied. Thus, for biomonitoring aquatic genotoxins under field conditions, the food web should also be considered.

Abstract: We investigated the ecology of peacock cichlids (Cichla spp.), diurnal piscovores and important gamefishes, in the Rio Cinaruco (Rio Orinoco drainage of the southern Venezuelan llanos) during the dry seasons of 1992-1993 and the Rio Pasimoni (Rio Negro-Amazonas drainage) during early 1993. In the Cinaruco, three Cichla species partitioned available habitats: C. intermedin near structure in primary river channel within or near swift current, C. orinocensis in shallow water along the shoreline of lagoons or slow channel reaches, and C. temensis in deeper waters along sandbanks and steeper rocky banks of lagoons and the river channel. During the dry season, C. orinocensis and C. temensis fed heavily on small characiform fishes, and C. intermedin consumed a variety of fishes, including loricariid catfishes. Only two peacock cichlids, C. orinocensis and C. temensis, were found in the Pasimoni, a more acidic and less seasonal ecosystem. These two species were larger in the Pasimoni compared with Cinaruco conspecifics; however, conspecifics from the two locations conformed to similar mass-length relationships. In both river systems, C. temensis were significantly larger than congeners, and C. temensis consumed larger prey than congeners in the Cinaruco. Examination of gonads and sizes of intraovarian oocytes indicated that reproduction by all five populations probably is initiated during the late low water period and may continue into the flooding period. Investigamos la ecologia de los pavones (Cichlidae, genero Cichla), picivores diurnos importantes en la pesca deportiva, en el Rio Cinaruco (cuenca del Rio Orinoco en el sur del estado Apure, Venezuela) durante la sequia de los alios 1992-1993, y del Rio Pasimoni (cuenca Rio Amazonas, estado Amazonas) de Venezuela durante los primeros meses del 1993. En el Cinaruco, tres especies de Cichla reparten los habitat disponibles: C. intermedin se ubica cerca de cobertura (arboles sumergidas, etc.) en el cauce principal cerca 0 dentro de la corriente rapida; C orinocensis se