Primer reporte del pez Amphilophus citrinellus (Perciformes: Cichlidae) en cuerpos de agua natural para República Dominicana

Se reporta por primera vez habitando de forma natural, la especie de pez ornamental Amphilophus citrinellus (Günther, 1864) para República Dominicana, en la presa de Hatillo, provincia Sánchez Ramírez. Se colectaron nueve especímenes y se utilizaron caracteres merísticos para su identificación. Se presume la introducción intencional de esta especie de alto potencial invasor en este cuerpo de agua.

Evolution in caves: selection from darkness causes spinal deformities in teleost fishes

Only few fish species have successfully colonized subterranean habitats, but the underlying biological constraints associated with this are still poorly understood. Here, we investigated the influence of permanent darkness on spinal-column development in one species (Midas cichlid, Amphilophus citrinellus ) with no known cave form, and one (Atlantic molly, Poecilia mexicana ) with two phylogenetically young cave forms. Specifically, fish were reared under a normal light : dark cycle or in permanent darkness (both species). We also surveyed wild-caught cave and surface ecotypes of P. mexicana . In both species, permanent darkness was associated with significantly higher rates of spinal deformities (especially in A. citrinellus ). This suggests strong developmental (intrinsic) constraints on the successful colonization of subterranean environments in teleost fishes and might help explain the relative paucity of cave-adapted lineages. Our results add depth to our understanding of the aspects of selection driving trait divergence and maintaining reproductive isolation in cave faunas.

Small size today, aquarium dumping tomorrow: sales of juvenile non-native large fish as an important threat in Brazil

ABSTRACT Informal sales of large-bodied non-native aquarium fishes (known as “tankbusters”) is increasing among Brazilian hobbyists. In this study, we surveyed this non-regulated trade on Facebook® from May 2012 to September 2016, systematically collecting information about the fishes available for trading: species, family, common/scientific names, native range, juvenile length, behavior, number of specimens available in five geographical regions from Brazil. We also assessed the invasion risk of the most frequently sold species using the Fish Invasiveness Screening Test (FIST). We found 93 taxa belonging to 35 families. Cichlidae was the dominant family, and most species were native to South America. All species are sold at very small sizes (< 10.0 cm), and most display aggressive behavior. The hybrid Amphilophus trimaculatus × Amphilophus citrinellus, Astronotus ocellatus, Uaru amphiacanthoides, Osteoglossum bicirrhosum, Cichla piquiti, Pangasianodon hypophthalmus, Datnioides microlepis and Cichla kelberi were the main species available. The southeast region showed the greatest trading activity. Based on biological traits, the FIST indicated that Arapaima gigas, C. kelberi and C. temensis are high-risk species in terms of biological invasions via aquarium dumping. We suggest management strategies such as trade regulations, monitoring, euthanasia and educational programs to prevent further introductions via aquarium dumping.

LUAS RELUNG DAN KOMPETISI PAKAN KOMUNITAS IKAN DI SITU PANJALU, JAWA BARAT

Penelitian ini bertujuan untuk mempelajari luas relung dan kompetisi komunitas ikan di Situ Panjalu. Pengambilan contoh ikan dilakukan pada bulan Mei dan September 2008 denganmenggunakan jaring insang berukuran 2,5; 3,0; dan 3,5 inci. Komunitas ikan di Situ Panjalu terdiri atas ikan nila (Oreochromis niloticus), kongo (Parachromis managuensis), oskar (Amphilophus citrinellus), golsom (Aequidens goldsom), selebra (Amphilopus sp.), dan keril (Aequidens rivulatus). Berdasarkan atas analisis luas relung dan kompetisi pakan, ikan golsom mempunyai potensi untuk berkembang menjadi populasi yang besar di perairan Situ Panjalu dibandingkan jenis ikan lain.Relung pakan yang dapat dioptimalkan adalah fitoplankton sehingga untuk pengkayaan stok dapat dilakukan melalui penebaran ikan herbivora pemakan plankton. The aim of the research was to identified niche breadth and competition among of fishes community in Situ Panjalu. Samples were collected by gill net of 2.5; 3.0; and 3.5 inches mesh size in Mei and September 2008. Fish community in Panjalu consist of tilapia (Oreochromis niloticus), kongo (Parachromis naguensis), midas cichlid (Amphilopus citrinellus), golsom (Aequidens goldsom), selebra (Amphilophus sp.) and keril (Aequidens rivulatus). Based on niche breadth and competition index, goldsom is potentially growth into great population compare to another fishes species in Panjalu. Food niche that could be optimimized was phytoplankton so that stock enhancement could be conducted by stocking the herbivorous fishes feed on phytolankton.

BEBERAPAASPEK BIOLOGI IKAN OSKAR (Amphilophus citrinellus) DI WADUK IR. H. DJUANDA, JATILUHUR, JAWA BARAT

Ikan oskar (Amphilophus citrinellus) telah berkembang pesat di Waduk Ir. H. Djuanda, di mana keberadaannya dianggap meresahkan pada kebanyakan nelayan setempat. Ikan ini mempunyai nilai ekonomis yang rendah dan bersifat omnivora-karnivora, diduga perkembangan ikan ini mampu mendesak perkembangan jenis ikan lainnya di perairan tersebut. Tujuan dari penelitian ini adalah untuk mengetahui beberapa aspek biologi ikan oskar, meliputi pola kebiasaan pakan ikan, tingkatkematangan gonad, dan fekunditas yang dilakukan di Waduk Ir. H. Djuanda, Jatiluhur. Penelitian ini dilakukan pada bulan Maret, Juni, Agustus, Oktober, dan Desember 2006. Pengambilan contoh ikan menggunakan gillnet percobaan dengan ukuran mata jaring 1; 1,5; 2; 2,5; 3; 3,5; dan 4 inci. Ikan oskardi waduk Ir. H. Djuanda merupakan ikan omnivora-karnivora yang memanfaatkan tumbuhan dan ikan sebagai pakan utamanya, larva serangga, dan fitoplankton sebagai pakan tambahan dan serangga, detritus dan zooplankton sebagai pakan pelengkap. Dari hasil pengamatan yang dilakukan didapatkan bahwa ikan oskar dapat berkembang dan bertelur sepanjang waktu dan fekunditasnya berkisar antara 1.595-3.567 butir. Oskar (Amphilophus citrinellus) has rapidly expanded in Ir. H. Djuanda Reservoir, where existence of the fish is assumed fretting by local fishermen. This fish has low economic value and the character is omnivore-carnivore, development anticipation of this fish can depress growth of other fish species in the territorial water. This research aims to know some biology aspects of Oskar in Ir. H. Djuanda Reservoir, such as food habit, level of gonad maturity, and fecundity. This study is conducted in March, June, August, October, and December 2006. Gillnet with mesh size of 1; 1.5; 2; 2.5; 3; 3.5; and 4 inch were used for fish sampling. This species is categorised in omnovora-carnivora fish feed mainly on plant and small fish, while insect larvae and phytoplankton as additional food and insect, detritus andzooplankton as complement food. From this study resulted thet oskar could develop and spawn in a long season with fecundity range from 1,595-3,567 grains.