The species composition and distributive characteristics of perciformes in Hau river basin in Can Tho city, Viet Nam

JOURNAL OF SCIENCE OF HNUE Natural Sci., 2011, Vol. 56, No. 7, pp. 160-168 THE SPECIES COMPOSITION AND DISTRIBUTIVE CHARACTERISTICS OF PERCIFORMES IN HAU RIVER BASIN IN CAN THO CITY, VIETNAM Dinh Minh Quang Can Tho University E-mail: dmquang@ctu.edu.vn Abstract. The study on the species composition of Perciformes in Hau river basin in Can Tho City, Vietnam, was conducted from August 2009 to May 2010 with a total sample of 432. These samples were collected in 7 sites in the dry and rainy seasons and lentic and lotic water systems by different methods and equipment. The samples were analysed and iden- tified by morphologic characteristics (7 measured indexes and 9 counted indexes). The taxonomy of these species were ordered by Fishbase taxo- nomic classification. The study found that there are 43 species belonging to 14 families (Ambassidae, Anabantidae, Channidae, Cichlidae, Coiidae, Eleotridae, Gobiidae, Helostomatidae, Nandidae, Osphronemidae, Polyne- midae, Scatophagidae, Sciaenidae and Toxotidae) and 31 genera. Among these species, Datnioides polota (Hamilton, 1822) and Toxotes chatareus (Hamilton, 1822) are indexed in Vietnam’s Red Data Book (2007). More- over, 9 commercial species, 17 estuarine species and 3 exotic species were found and complemented 8 species for the study area. The result of study is believed to be essential and pivotal to the management and use of the bio-diversity of this order of fish. Keywords: Perciformes, commercial species, estuarine species, threatened species, exotic species, lentic water ecosystem and lotic water ecosystem. 1. Introduction Can Tho City has a diverse system of rivers, ponds and canals which are controlled by the Hau river basin leading to the composition of fish, especially Per- ciformes, which is diverse. Furthermore, a lot of species of this order have been used not only for food but also for entertainment and medicine. In the same way, the fisheries in this area are diverse and bring a strong economic income for the local communities. However, fish sources have recently sharply reduced because of 160 The species composition and distributive characteristics of Perciformes... the polluted environment and over exploitation, especially the exploitation by juve- niles. As a result, the species composition and quantity of this order have gradually suffered irreversible changes. Moreover, there has been little research on the com- position of Perciformes for many years in this area. Therefore, it is important to study the composition of Perciformes to have accurate assessment on their quality, composition and distribution, compared with past published findings to consider whether and how the polluted environment and non-scientific fishing methods may have caused impacts on the fish composition in which species are threatened and may be in the danger of extinction. 2. Content 2.1. Study site and time period ∗ Study site The samples were collected at seven sites along the Hau river basin in Can Tho City which included Hung Phu (Cai Rang District), An Thoi (O Mon District), Thuan Hung (Thot Not District), Nhon Ai (Phong Dien District), Trung Hung (Co Do District), Thoi Lai (Thoi Lai District) and Vinh Trinh (Vinh Thanh District) (Figure 1). Figure 1. Sample collection area ∗ Time of study This survey was made from 8/2009 to 05/2010 including sample collecting, interviews with fishermen and local people in the rainy and dry seasons in field trips and sample analyzing and identifying time in the Animal Laboratory, Department of Biology Education, School of Education, Can Tho University. 161 Dinh Minh Quang 2.2. Materials and methods ∗ Materials - Fishing-nets, fishing-rods, buckets, plastic bags, a camera and interviewing papers. - Formalin was used as a main chemical for storing samples. ∗ Methods - Sample collection: Samples were collected in seven sites in the dry and rainy seasons, lentic and lotic water systems by different methods and equipment (fishing-nets, fishing-rods). Fishermen and local people were also invited to collect fish samples. Moreover, I made interviews with fishermen and local people to gain information relating to fish in this area [7]. - Sample protection: Samples were fixed in 10% formalin and stored in 5% formalin [7]. - Sample analyzation: Samples were analyzed by morphologic characteristics (7 measured indexes and 9 counted indexes) [5]. - Sample identification: The main reference for identification was the book of Identification of Fresh Water Fish of the South of Mai Dinh Yen [8]. I also used other references for identification of some biologists for example [2-4, 6, 8-10]. - Sample taxon: Taxonomic orders were determined and classified by the Fish- based Species Classification [11]. 2.3. Results 2.3.1. Distribution of 43 species according to seasons and ecosystems After 9 months studying and classifying 342 samples, I found that there were 43 species belonging to 31 genera and 14 families and their distribution (Table 1). Table 1. Distribution of fish depending on seasons and ecosystems Distribution No. Scientific name English name Seasons Ecosystems Note Rain Dry Lentic water Lotic water Percoidei 1. Ambassidae 1 Ambassis gymno- cephalus (Lacepede, 1802) Bald glassy + + + * 2 Parambassis wolffii (Bleeker, 1851) Duskyfin glassy perchlet + + + * 162 The species composition and distributive characteristics of Perciformes... 2. Coiidae 3 Datnioides polota (Hamilton, 1822) Siamese Tiger- fish + + VU 3. Sciaenidae 4 Nibea soldado (Lacpde, 1802) Soldier croaker + + * 4. Polynemidae 5 Eleutheronema tetradactylum (Shaw, 1804) Fourfinger threadfin ⋆ 6 Polynemus par- adiseus Linnaeus, 1758 Paradise threadfin + + + * 7 Polynemus dubius Bleeker, 1854 Eastern Par- adise fish + + + * 5. Toxotidae 8 Toxotes chatareus (Hamilton, 1822) Spotted Archer- fish + + + + VU 6. Nandidae 9 Pristolepis fasciata (Bleeker, 1851) Malayan leaffish + + + + 10 Nandus nandus (Hamilton, 1822) Gangetic leaffish ⋆ 7. Scatophagidae 11 Scatophagus argus (Linnaeus, 1776) Spotted scat ⋆ Labroidei 8. Cichlidae 12 Oreochromis mossambicus (Pe- ters, 1852) Mozambique tilapia + + I 13 Oreochromis niloti- cus niloticus (Lin- naeus, 1758) Nile tilapia + + + + I Gobioidei 9. Eleotridae 14 Eleotris fusca (Schneider & Forster, 1801) Dusky sleeper + + 163 Dinh Minh Quang 15 Eleotris oxycephala Temminck & Schlegel, 1845 Egg sleeper + + + 16 Butis butis (Hamil- ton, 1822) Duckbill sleeper + + 17 Oxyeleotris mar- morata (Bleeker, 1852) Marbled sleeper + + + + 18 Oxyeleotris uroph- thalmus (Bleeker, 1851) Coconut sleeper + + + 10. Gobiidae Gobiinae 19 Glossogobius giuris (Hamilton, 1822) Gangetic tank goby + + + * 20 Glossogobius sparsi- papillus Akihito & Meguro, 1976 Linecheek tank goby + + + * 21 Glossogobius aureus Akihito & Meguro, 1975 Golden tank goby + + + * 22 Acentrogobius viridipunctatus (Valenciennes, 1837) Spotted green goby + + + * Gobionellinae 23 Stenogobius genivit- tatus (Valenciennes, 1837) Chinstripe goby + + + * 24 Eugnathogobius oligactis (Bleeker, 1875) Black goby + + + * 25 Awaous grammepo- mus (Bleeker, 1849) Scribbled goby + + * 26 Oxyurichthys mi- crolepis (Bleeker, 1849) Maned goby + + + * 27 Oxyurichthys sp. Large-maned goby + + + * Oxudercinae 164 The species composition and distributive characteristics of Perciformes... 28 Pseudapocryptes elongatus (Cuvier, 1816) Pointed-tailed goby + + + * 29 Parapocryptes ser- peraster (Richard- son, 1846) Largescaled goby + + + * 30 Boleophthalmus bod- darti (Pallas, 1870) Boddart’s goggle-eyed goby ⋆ 31 Periophthalmodon schlosseri (Pallas, 1770) Giant mudskip- per + + + * Anabantoidei 11. Anabantidae 32 Anabas testudineus (Bloch, 1792) Climbing Perch + + + + 12. Helostomati- dae 33 Helostoma tem- minkii Cuvier, 1829 Kissing Gourami + + I 13. Osphronemi- dae 34 Trichopsis vittata (Cuvier, 1831) Croaking Gourami + + + 35 Betta splendens Re- gan, 1910 Siamese fighting fish + + + 36 Betta taeniata Re- gan, 1910 Borneo betta + + + 37 Trichogaster mi- crolepis (Gunther, 1861) Moonlight gourami + + + 38 Trichogaster tri- chopterus (Pallas, 1770) Three spot gourami + + + 39 Trichogaster pec- toralis Regan, 1910 Snakeskin gourami + + + + 40 Osphronemus goramy Lacpde, 1801 Giant gourami + + Channoidei 14. Channidae 165 Dinh Minh Quang 41 Channa micropeltes (Cuvier, 1831) Indonesian snakehead + + + 42 Channa striata (Bloch, 1793) Striped snake- head + + + + 43 Channa lucius (Cu- vier, 1831) Splendid Snake- head + + + + Legend. (VU): Threatened species; (I): Exotic species; (*): Estuarine species; (⋆): Not seen again species; (+): Present. Table 1 shows species composition of Perciformes in the study area as follows: - There were nine commercial fish species including Marbled Sleeper, Pointed- tailed goby, Largescaled goby, Climbing perch, Kissing gourami, Snakeskin gourami, Giant gourami, Indonesian snakehead and Striped snakehead. Three exotic species i.e., Mozambique tilapia, Nile tilapia and Kissing gourami were found. Two species, Siamese Tigerfish and Spotted archerfish, were indexed in Vietnam’s Red Data Book, 2007 (VU level). - There were 17 estuarine species such as Bald glassy, Duskyfin glassy per- chlet, Soldier croaker, Paradise threadfin, Eastern paradise fish, Gangetic tank goby, Linecheek tank goby, Golden tank goby, Spotted green goby, Chinstripe goby, Black goby, Scribbled goby, Maned goby, Large-maned goby, Pointed-tailed goby, Largescaled goby and Giant mudskipper. - Compared to study of Khoa and Huong [6], 4 species i.e., Fourfinger Threadfin, Spotted Scat, Gangetic leaffish and Boddart’s goggle-eyed goby were not seen again in the study. However, I complemented 8 species such as Soldier croaker, Mozam- bique tilapia, Nile tilapia, Dusky sleeper, Linecheek tank goby, Scribbled goby, Kiss- ing gourami and Giant gourami in this area. Industrialization and Modernization have lead to a change in the fishs life environment, which influenced the distribution of fish. Furthermore, Fish is an imigrated species so that with time and location where I collected many species, by now they may have moved. These were the main causes of these differences. - The number of species composition of Perciformes distributed in lotic water ecosystem (36 species) was larger than that in lentic water ecosystem (11 species), whereas the corresponding figure in the rainy and dry seasons was almost equal, 34 species and 36 species, respectively. 166 The species composition and distributive characteristics of Perciformes... 2.3.2. Diversity of species composition of Perciformes The abundance of the composition of Perciformes is presented in Table 2. Table 2. Quantity and percentage of genus and species belonging to families No. Scientific name Quantity Percentage Genus Species Genus Species 1 Gobiidae 10 13 32.26 30.23 2 Osphronemidae 4 7 12.90 16.28 3 Eleotridae 3 5 9.68 11.63 4 Polynemidae 2 3 6.45 6.98 5 Channidae 1 3 3.23 6.98 6 Ambassidae 2 2 6.45 4.65 7 Nandidae 2 2 6.45 4.65 8 Cichlidae 1 2 3.23 4.65 9 Coiidae 1 1 3.23 2.33 10 Sciaenidae 1 1 3.23 2.33 11 Toxotidae 1 1 3.23 2.33 12 Scatophagidae 1 1 3.23 2.33 13 Anabantidae 1 1 3.23 2.33 14 Helostomatidae 1 1 3.23 2.33 - With regards to the family level, among the 14 families, Gobiidae had the largest number of genus (10 genera), made up 32.26%, followed by Osphronemidae (4 genera) and Eloetridae (3 genera) occupied 12.9% and 9.68%, respectively. Am- bassidae, Nanidae and Polynemidae shared the same pattern, which was 2 genera and accounted for 6.45%. The rest of the families included 1 genus and amounted to 3.23%. - With regards to genus level, among 31 genera, there were 9 multi-species genera and 22 single-species genera. Trichogaster, Channa and Glossogobius had the greatest proportion of species, which was 3 species and made up 6.98%. Betta (Eleotris, Oreochromis, Oxyeleotris, Oxyurichthys and Polynemus) followed closely, with 2 species and accounted for 4.65%. The others included 1 species and occupied 2.33%. - In terms of the species level, among the 43 species, Gobiidae was the largest (13 species), amounted to 30.23%, whereas the opposite was true in Anabantidae, Coiidae, Helostomatidae, Scatophagidae, Sciaenidae and Toxotidae, which included 1 species and made up 2.33%. Osphronemidae ranked second, followed by Eleotridae, 16.28% (7 species) and 11.93% (5 species), respectively. 167 Dinh Minh Quang 3. Conclusion After 9 months studying on the species composition of Perciformes in Hau river basin in Can Tho City, the result was gained as follows: - There were 43 species of Perciformes belonging to 31 genera and 14 families in Hau river basin in Can Tho City. Among them, there were 2 species were listed in Vietnam’s Red Data Book, 2007 (VU level), 3 exotic species, 9 commercial fish and 17 estuarine species. - Complemented 8 species for this area in comparison with the study of Khoa & Huong [6]. - The abundance of the composition of Perciformes in lotic water ecosystem was high. REFERENCES [1] Ministry of Science, Technology and Environment, 2007. Vietnam’s Red Data Book (Animal part). Science and Technology Publishing House, Ha Noi, (in Viet- namese). [2] Nguyen Van Hao & Ngo Sy Van, 2001. Fresh warter fish of Vietnam. Vol. I. Agriculture Publishing House, Ha Noi, (in Vietnamese). [3] Nguyen Van Hao, 2005. Fresh warter fish of Vietnam. Vol. II. 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