San hô mềm (Alcyonacea) ở vịnh Nha Trang

Hgi nghi Khoa hgc ky niem 35 ndm Vien Khoa hgc vd Cong nghe Viet Nam - Hd Ngi 10'2010<br /> <br /> <br /> <br /> SAN H O M E M (ALCYONACEA) 6 VINH N H A T R A N G<br /> SOFT CORALS (OCTOCORALLIA: ALCYONACEA) IN NHA TRANG BAY:<br /> SPECIES DIVERSITY AND DISTRIBUTIONAL PATTERNS<br /> Hoang Xuan Ben<br /> Vien Hai Duong Hoc, 01 Cau Da - Nha Trang - Khanh Hda.<br /> Email: hxuanben(a)vahoo.com<br /> Tom tat:<br /> Nghien ciru vi da dgng sinh hoc cua san hd mim (Alcyonacea) a Viet Nam ndi<br /> chung cdn rdt nhiiu hgn chi. Ddy Id kit qud nghien ciru ddy du nhdt vi da dgng<br /> sinh hoc cua san hd mem a Vinh Nha Trang. Kit qud ddphdn tich 191 mdu vd xdc<br /> dinh dugc 76 lodi san hd mim thudc 20 gidng vd 9 ho. Tdng hgp tdt cd cdc kit<br /> qud nghien cuu cho phep xdc dinh 142 lodi thudc 30 gidng vd 11 ho san hd mim<br /> a Vinh Nha Trang. Hdn Vung vd Hdn Mieu la hai nai cd sd lugng lodi cao nhdt<br /> ciing cd 27 I odi, tiip din Id Hdn Cau, Hdn Mun vd Hdn Tdm. Bdi Ldn vd Hdn<br /> Riia Id nai cd thdnh phdn lodi khd thdp, Miii Chut chi ^hi nhdn dugc 2 lodi.<br /> Gidng Sinularia cd sd lodi nhiiu nhdt vai 34 lodi, tiep din Id Sarcophyton - 13<br /> lodi, Lobophytum - 7 lodi, Hon Mun la nai cd sd lugng lodi thudc gidng Sinularia<br /> cao nhdt vai 13 lodi, tiep din Id Hdn Tdm vd Hdn Miiu ciing cd 10 lodi. Vai<br /> nghien ciru ndy, 32 lodi san hd mim dugc ghi nhdn ldn ddu cho Vinh Nha Trang.<br /> Hdn Mpt vd Hdn Miiu Id nai cd sd lodi mai ghi nhgn nhieu nhdt cimg cd 10 lodi,<br /> cdc diem cdn lgi dao ddng tir 5 - 8 lodi. Kit qud nghien cuu cho thdy khu hi san<br /> hd mem a Vinh Nha Trang thudc vdo logi da dgng. Su thay ddi ve thdnh phdn lodi<br /> theo thai gian a mot sd diim nghien ciru a Miii Chut, Hdn Miiu, Hdn Tdm, Hdn<br /> Mot, Hdn Riia vd Nam Hdn Tre Id khd lan. Tdt cd cdc diem khdo sdt deu gidm vi<br /> sd lugng cUng nhu cd su thay ddi trong thdnh phdn lodi, vdn di ndy cdn dugc<br /> thdo ludn them khi cd cdc nghien ciru sdu vd chi tiit han.<br /> Abstract:<br /> Research on biodiversity of soft corals (Alcyonacea) in Vietnam in general is<br /> very much limited. Here is the most complete review of species richness of soft<br /> corals in Nha Trang bay. Based on the collection of 191 samples 76 species<br /> belong to 20 genera and 9 families are identfied. The survey have contributed to<br /> complete the list of 142 species belong to 30 genera and II families of soft corals<br /> in Nha Trang bay. The most diversity is recorded around Vung and Mieu islands,<br /> 27species in each site. There are only 2 species observed in Mui Chut. Sinularia<br /> genus is common in Nha Trang bay with 34 species, followed by Sarcophyton with<br /> 13 species and Lobophytum - 7 species, Mun island has the 13 of species<br /> belonging to Sinularia genus, Mieu and Tam islands has 10 species each site.<br /> Among the 76 listed species of this survey 32 species are firstly recorded in Nha<br /> Trang bay. Mot and Mieu islands occupied the highest number of newly recorded<br /> species with 10 species at each site. The result showed that of soft coral is high<br /> diversity in Nha Trang bay. The composition of soft corals change with time at<br /> some site such as Mui Chut, Mieu, Tam, Mot, Rua Island, and this problem should<br /> be discussed further in future studies.<br /> <br /> 1. Tai lieu va phu-ong phap nghien cihi<br /> 1.1. Vi tri vd thai gian thu mdu: Tiln hanh thu thap mau san hd mim tai 10 vj tri: Mui<br /> Chut, Hdn Miiu, Hdn Tim, Hdn Mot, Hdn Mun, Bai Lan, Bai Bang, Hdn Vung, Hdn Cau.<br /> Cac vi tri khao sat nay dugc chon lira tren ca sd kl thira cac khao sat thu mau trudc day eiia<br /> <br /> 275<br /> Tieu ban: Khoa hgc cong nghe Bien ISBN: 978-604-913-015-1<br /> <br /> <br /> Tixier-Durivault (1970), WWF (1994). Ba dilm cdn lai la Hdn Cau. Hdn Vung, Bai Bang la<br /> nhung noi cd do phii san hd mem cao nhat ciia Vjnh Nha Trang theo kit qua danh gia nhanh<br /> (manta tow) vl hien trang do phii ran san hd (Hinh 1).<br /> 7.2. Phirang phdp thu mdu: Diing thiet bj lan SCUBA bai ngau nhien va thu cac mau<br /> bang each cat mot phan tap doan ddi vdi tap doan kich thudc ldn hoac thu toan bd ddi vdi tap<br /> doan cd kich thudc nhd bat gap tir do sau 0,5 m den het khu vuc cd phan bd ran san hd. Cac<br /> mau dugc danh sd va chup hinh dudi nude de sir dung cho viec md ta hinh thai ngoai. Tdng<br /> sd mau thu dugc cho nghien ciiu nay la 191 mau.<br /> 1.3. Bdo qudn xir li vd phdn tich mdu; mau san hd sau khi thu dugc ngam trong<br /> Formalin 10% trong 24 gid sau dd rira sach va bao quan trong cdn 70%. Cit tirng phan khac<br /> nhau ciia tap doan san hd ngam rieng biet vao dung djch Chlorine \0% trong vdng 30 phiit dl<br /> tay phan thjt. Sau dd, loc lay cac tram xuong. Xac djnh cac dang tram xuong khac nhau tren<br /> kinh hien vi cd do phdng dai tir 1 0 x 4 , 10 x 10. Mdt sd dac diem khac ciia tap doan (kich<br /> thudc, khoang each polyp, sd lugng cac Siphonozooid...) dugc xac djnh tren kinh liip. Cac<br /> tram dugc chup anh tren kinh hien vi ddi vdi nhirng loai ghi nhan lan dau tien d vjnh Nha<br /> Trang. Xac djnh thanh phan loai dua theo cac tai lieu phan loai ciia cac tac gia Verseveldt<br /> (1980,1982,1983), Ofwegen et al. (1991), Ofwegen (1987,1996,' 2002, 2008a, 2008b), Tixer-<br /> Durivault (1967, 1970), Roxas (1933a, 1933b), Dautova & Savinkin (2009), Manuputty et al.<br /> (2007), Grasshoff (2000, 2001).<br /> <br /> <br /> H6n Rua<br /> Hon Cau<br /> <br /> <br /> <br /> H6n Vung<br /> <br /> <br /> <br /> <br /> f#>a Trana<br /> Bdng<br /> <br /> <br /> <br /> <br /> H6n Mun<br /> <br /> <br /> <br /> <br /> Hinh I; Sa dd vi tri (•) thu mdu san hd mim vinh Nha Trang<br /> 2. Ket qua nghien ciru<br /> 2.1. Dgc diem ve thdnh phan lodi<br /> Phan tich 191 mau san hd mim cho phep xac djnh 76 loai thudc 20 gidng va 9 ho. Cd<br /> 6 taxon chi xac djnh dugc den gilng. Hdn Vung va Hdn Miiu la hai khu vuc cd sd lugng loai<br /> san hd mim nhieu nhat ciing 27 loai, tilp din la Hdn Cau, Hdn Mun va Hdn Tim. Bai Lan va<br /> Hdn Riia la nod cd thanh phin loai kha thip, tuong img la 10 va 14 loai. 6 Mui Chut chi ghi<br /> nhan dugc 2 loai thudc 2 giong va 1 ho (Bang 1). Ting hgp cac ket qua nghien cim trudc day<br /> 276<br />  Hgi nghi Khoa hgc ky niem 35 ndm Vien Khoa hgc vd Cong nghe Viet Nam - Hd Ngi 102010<br /> <br /> <br /> <br /> ciia Stiasny (1938) Tixier-Durivault (1970) va WWF (1994) [13,14,20] va nghien cim nay cho<br /> phep xac djnh 142 loai thudc 30 gidng va 11 ho san hd mim d Vjnh Nha Trang.<br /> Bdng 1: Sd lugng lodi san hd mim a cdc diim khdo sdt<br /> Diem khao sat Ho Giong Loai<br /> Hdn Cau 5 10 25<br /> Hdn Vung 7 14 27<br /> Hdn Riia 4 8 14<br /> Hdn Mun 4 8 25<br /> Hdn Mot 3 8 18<br /> Hdn Tam 5 9 24<br /> Hdn Mieu 4 10 27<br /> Bai Bang 5 10 19<br /> Bai Lan 3 6 10<br /> : I<br /> <br /> Miii Chut j 1 2 2<br /> Tong so 9 20 76<br /> Chi tiet ve thanh phan loai cho thay, ho Alcyoniidae cd sd lugng loai nhieu nhat vdi<br /> 57 loai, tiep den la ho Nephtheidae 6 loai, ho Plexauridae 5 loai. Cac ho cdn lai chi cd tir 1 - 3<br /> loai. Xet ve tirng gidng, gidng Sinularia cd sd lugng loai nhieu nhat la 34 loai chiem ti le<br /> 44,7% sd lugng loai, gidng Sarcophyton cd 13 loai chiem 17,11%), Lobophytum cd 7 loai<br /> chiem 9,2%, cae gidng cdn lai chi cd tir 1 den 2 loai.<br /> Kit qua nghien ciiu ghi nhan dugc 32 loai thudc 12 gidng va 6 hg san hd mem ghi<br /> nhan lan dau cho Vjnh Nha Trang. Trong sd dd gidng Sinularia cd sd loai nhieu nhat la 14<br /> loai, tiep den la Sarcophyton 7 loai, hai gidng nay chiem tren 70% tdng sd loai mdi ghi nhan<br /> cho khu vuc nghien ciiu. Ket qua ciing cho thay, Hdn Mot va Hdn Mieu la nai cd sd loai mdi<br /> ghi nhan nhieu nhat ciing cd 10 loai, cac diem cdn lai dao ddng tir 5 - 8 loai. Ddi vdi gidng<br /> Sinularia, hien nay ngudi ta da thdng ke tren the gidi cd khoang 128 loai [8], tuy nhien chi<br /> trong thdi gian tir 2007 - 2009 rieng viing bien Thai Binh Duong da ghi nhan them hon 25<br /> loai mdi cho the gidi. Dieu nay cho thay day la gidng rat da dang ve thanh phan loai. Vi vay,<br /> trong kit qua nghien ciiu nay ghi nhan them 14 loai mdi cho khu he Vjnh Nha Trang ciing la<br /> dilu khdng liy gi lam ngac nhien so vdi 38 loai ma Tixier-Durivault (1970) da xae djnh trudc<br /> day. Vdi gidng Sarcophyton, the gidi da ghi nhan tren 35 loai [18]; nghien cim ciia Tixier-<br /> Durivault (1970) xac djnh d Nha Trang cd 9 loai, nghien ciiu nay bd sung them 7 loai va nang<br /> tdng sl loai thudc gidng nay d Vjnh Nha Trang la 16 loai. So vdi ket qua nghien cim ciia<br /> Tixier-Durivault (1970) cho thay chi sd gidng nhau ve thanh phan loai giira 2 dgt nghien cuu<br /> la kha thap. Thanh phan loai giiia hai dgt nghien cim tao thanh hai nhdm doe lap vdi chi sd<br /> gidng nhau dat 12,46%. Nhu vay, cd sir thay ddi thanh phan loai san hd mem theo thdi gian.<br /> 2.2. Ddc diem ve phdn bd<br /> Q mirc do gidng, Lobophytum la gidng cd sd lan xuat hien cao nhat d 10/10 diem khao<br /> sat, kl den la 2 gidng Sarcophyton va Sinularia 9/10 diem khao sat, r^c gilng Briaeum,<br /> Euplexaura, Paraplesaura, Subergorgia vk Heteroxenia chi xuit hien 1 lan. C) mirc do loai.<br /> <br /> 277<br /> Tieu ban: Khoa hgc cong nghe Bien ISBN: 978-604-913-015-1<br /> <br /> <br /> loai Lobophytum batarum cd tan sd xuat hien cao nhat II 10 dilm khao sat. loai Sarcophyton<br /> acutum, S. crassum, S. glaucum, Sinularia fiexibilis vd Riimphella aggregata 6/ 10 diem khao<br /> sat, cac loai cdn lai cd tan sd xuat hien thap. Cd 32 loai chi xuit hien 1 lin trong 10 tram khao<br /> sat. Hdn Mun la noi cd sd lugng loai thudc gidng Sinularia nhieu nhit vdi 13 loai. tiep den la<br /> Hdn Tam va Hdn Mieu ciing ed 10 loai, Hdn Riia chi cd 2 loai va Miii Chiit khdng ghi nhan<br /> loai nao thudc gidng nay. Cac loai thudc gidng Sarcophyton xuat hien tuong ddi deu giua cac<br /> diem thu mau, dao ddng tir 4 - 6 loai. Cac loai thudc gidng Lobophytum ghi nhan cao nhat tai<br /> Hdn Mieu vdi 4 loai, cac diem cdn lai chi ghi nhan tir 1 - 2 loai. Miic do gidng nhau ve thanh<br /> phan loai d cac tram khao sat dugc tinh toan va cho ket qua tren hinh 2. O mirc gidng nhau<br /> tren 50%, 2 nhdm tram dugc hinh thanh. Nhdm 1 la cac vj tri khao sat Bai Bang va Hdn Vung<br /> d xa bd va nhdm 2 la cac vi tri Hdn Tam va Hdn Mieu nam tuong ddi gan bd.<br /> <br /> <br /> <br /> <br /> Hinh 2: Mirc do gidng nhau vi thdnh phdn lodi san hd mim a cdc trgm khdo sdt.<br /> 3. Ket luan<br /> 3.1. Nghien ciiu nay da xac djnh dugc 76 loai thudc 20 gidng va 9 ho san hd mim.<br /> Tdng hgp tat ca cac ket qua nghien ciiu ve san hd mim Vjnh Nha Trang cho thiy sl lugng<br /> loai san hd mem d khu vuc nay la 142 loai thudc 30 gidng va 11 ho. Hdn Vung va Hdn Mieu<br /> la hai noi cd sd lugng loai cao nhit cimg cd 27 loai, tilp din la Hdn Cau, Hdn Mun va Hdn<br /> Tim. Cac diem Bai Lan, Hdn Riia va Mui Mui Chut la noi cd thanh phin loai thip.<br /> 3.2. Gidng Sinularia cd sd loai nhilu nhat vdi 34 loai, tilp din la Sarcophyton - 13<br /> loai, Lobophytum - 7 loai. Hdn Mun la noi cd sd lugng loai thudc giong Sinularia cao nhit cd<br /> 13 loai, tiep den la Hdn Tim va Hdn Miiu ciing cd lo loai.<br /> 3.3. Cd 32 loai san hd mim ghi nhan lin diu cho Vjnh Nha Trang. Hdn Mot va Hdn<br /> Mieu la noi cd sd loai mdi nhilu nhit ciing cd 10 lorn, cae dilm cdn lai dao ddng tir 5 - 8<br /> loai.<br /> 3.4. Tat ca cac diem khao sat deu giam vl so lugng loai cung nhu cd sir thay doi trong<br /> thanh phan loai so vdi cae nghien cim trudc day. Vin dk nay cin dugc thao luan them khi cd<br /> cac nghien ciiu sau va chi tilt hon.<br /> TAI LIEU THAM KHAO<br /> 1. Dautova, T. & Savinkin O., New data on soft coral from Nha Trang Bay Zootaxa<br /> 2027: l-27pp (2009).<br /> Grasshoff. M & Bargibant. G, Coral reef Gorgonians of New Caledonia. Institut De<br /> Recherche Pour le Developpement, Paris. 335pp (2001).<br /> Grasshoff . M, The Gorgonians of the Sinai coast and the Strait of Gubal, Red sea<br /> <br /> 278<br />  Hgi nghi Khoa hgc ky' niem 35 ndm Vien Khoa hgc vd Cdng nghe Viet Nam - Hd Ngi 10/2010<br /> <br /> <br /> <br /> (Coelenterata Octocorallia). Courier Forschungsinstitut Senckenbergiana. Frankfurt<br /> am Main, 126pp(2000).<br /> 4. Manuputty Y. & Ofwegen L.P. van. The genus Sinularia (Octocorallia: Alcyonacea)<br /> from Ambon and Seram (Moluccas, Indonesia).— Zoologisehe Mededelingen Leiden<br /> 81(11): 187-216(2007).<br /> 5. Ofwegen L.P. van & Vennam J., Notes on Octocorallia from the Laccadives (SW<br /> India). Zool Meded Leiden 65: 143-154 (1991).<br /> 6. Ofwegen, L.P. van, Melithaeidae (Coelenterata; Anthozoa) from the Indian Ocean<br /> and the Malay Archipelago.— Zool. Verb. Leiden 239: 3- 57 (1987).<br /> 7. Ofwegen, L.P. van, Octocorallia from the Bismark Sea (part II). Zoologisehe<br /> Mededelingen Leiden, 70, 207-215 (1996).<br /> 8. Ofwegen, L.P. van. Status of knowledge of the Indo Pacifi c soft coral genus Sinularia<br /> May, 1898 (Anthozoa; Octocorallia),— Proceedings 9th International Coral Reef<br /> Symposium, Bali, 2000, 1: 167-171 (2002).<br /> 9. Ofwegen, L.P. van. The genus Sinularia (Octocorallia: Alcyonacea) from Bremer and<br /> West Woody islands (Gulf of Carpentaria, Australia, Zool. Med. Leiden 82 (16),<br /> l.i.2008: 131-165(2008).<br /> 10. Ofwegen, L.P. van. The genus Sinularia (Octocorallia; Alcyonacea) at Palau,<br /> Micronesia.Zool Med. Leiden 82 (51), 31.xii.2008: 631-735 (2008).<br /> 11. Roxas, H.A., Philippine Alcyonacea, 1 Families Comularia and Xeniidae, The<br /> Philippine Journal of Science, Vol. 50 (1). 49 - 1 lOpp (1933).<br /> 12. Roxas, H.A., Philippine Alcyonacea, II Families Alcyoniidae and Nephthyidae.The<br /> Philippine Journal of Science, Vol. 50 (4). 345 - 483pp (1933).<br /> 13. Stiasny G., Franzosisch Indochina Gesammelten Gogornarien, Memori de Museum<br /> National D'histoire Naturelle. Nouvelle serie, Tom VI : Fascicule 3, 356 - 368 pp<br /> (1938).<br /> 14. Tixier-Durivault, A., Les Octocoralliaires de Nha Trang (Vietnam), Cahiers du<br /> Pacifique 14 : 115 - 236pp (1970).<br /> 15. Tixier-Durivault, A., Les Alcyonaires du Museum. I. Famille des Alcyoniidae, 4,<br /> Genre Lobophytum, Bull. Mus.nat. Hist.nat. Paris, (2) 28 (4): 401 - 405pp (1956).<br /> 16. Tixier-Durivault, A., Revision de la Famille des Alcyoniidae: les genres Sarcophyton<br /> et Lobophytum, Zool. Verhand, 36 : 1 - 180pp (1958).<br /> 17. Verseveldt J., A revision of the genus Sinularia May (Octocorallia: Alcyonacea).<br /> Zool, Verb. Leiden 179: 1-128 (1980).<br /> 18. Verseveldt J., A revision of the genus Sarcophyton Lesson (Octocorallia; Alcyonacea).<br /> Zool. Verb. Leiden 192: 1-91(1982).<br /> 19. Verseveldt J., A revision of the genus Lobophytum von Marenzeller (Octocorallia;<br /> Alcyonacea). Zool. Verh.Leiden 200: 1-103 (1983).<br /> 20. WWF Vietnam Marine Conservation Southern Survey Team, Survey report on the<br /> Biodiversity, Resource Utilization and Conservation Potential of Cat Ba, Hon Mun,<br /> Cu Lao Cau, An Thoi, Co To, Con Dao. Institute of Oceanography (Nha Trang, Hai<br /> phong, Vietnam) and WWF, Unpublished report, 95p (1994).<br /> <br /> <br /> <br /> <br /> 279<br />