Marine Research in Indonesia (MRI - E-Journal)
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THE EXTENDED LONGEVITY OF A SMALL CORAL REEF SERRANID; A LESSON FROM CEPHALOPHOLIS CYANOSTIGMA (BLUE SPOT ROCK COD) OF THE CENTRAL GREAT BARRIER REEF, AUSTRALIA
The blue spot rock cod, Cephalopholis cyanostigma, is a small common coral reef serranid that forms a significant proportion of the discarded by-catch in the Great Barrier line fishery. Samples were obtained by spear and line fishing at Orpheus Island (range 114- 294 mm FL, mean = 226 mm, n = 137) and from Pelorus Island (range 120-285 mm FL, mean = 214 mm, n = 125). Sagittal otoliths were used to obtain age-based parameter estimates for the populations at each island. Analysis of marginal increments on monthly samples suggested that a single opaque band was deposited annually during November - December. Recaptures of three fishes (9,18, and 24 years old) in July and November 1997, five years after injection of oxytetracycline, further corroborated our conclusion that band formation was annual. The maximum age in our samples of 31 years suggested that the blue spotted rock cod was one of the longest lived serranids documented to date. The von Bertalanffy growth function provided the best description of the pattern of growth for populations at both islands with high coefficients of determination (R2 = 0.86 and 0.82 for Orpheus and Pelorus islands, respectively). Female population of both sites grew relatively slow, not reaching asymptotic size until 7-10 yrs. Statistical comparisons on male and female growth patterns were not significant, however. There were significant differences in growth parameters between islands with C. cyanostigma on average growing larger at Orpheus Island (L?= 258 mm and K= 0.22) compared with Pelorus Island (L?=244 mm and K = 0.25). These age-based population parameter estimates indicated that C. cyanostigma was considerably longer lived than expected for a small coral reef serranid and further demonstrated the utility of age-based methods in studies of the demography of tropical reef fish. The implication for conservation and fisheries management of small tropical serranids is that species with similar population parameters are likely to sustain much lower levels of fishing mortality than previously thought
THREE SPECIES OF SARGASSUM (PHAEOPHYCEAE) WITH COMPRESSED PRIMARY BRANCHES IN THE GULF OF THAILAND
Three species of Sargassum with compressed primary branches, S. binderi Sonder, S. oligocystum Montagne and S. swartzii (Turner) C.A. Agardh, have been described from the Gulf of Thailand. S. swartzii is the first record of this species from the coast of Thailand. A key for these three species and for each species descriptions have been completed. The clear distinction among these three species is clearly shown and discussed. S. binderi has slender lanceolate leaves, a dentate margin along the compressed stem of its vesicles, and clear spines along the whole margin of the flattened receptacles. S. oligocystum has broader lanceolate leaves with an acute to rounded apex, almost entire, spherical vesicles, and only few spines on the margin of the slightly compressed receptacles. S. swartzii has linear lanceolate leaves, pointed or crowned vesicles, and few spines neat the tip of its almost terete receptacles
SIZE, SEX AND LENGTH AT MATURITY OF FOUR COMMON SHARKS CAUGHT FROM WESTERN INDONESIA
A study on four common shark species in Indonesia, the spinner shark Carcharhinus brevipinna (Muller and Henle, 1839), silky shark Carcharhinus falciformis (Bibron, 1839), spot-tail shark Carcharhinus sorrah (Valenciennes, 1839) and scalloped hammerhead Sphyrna lewini (Griffith and Smith, 1834) was conducted at several shark landing sites in western Indonesia from March 2002 to December 2004. Data were collected from the surveyed areas including the length of frequency, sex composition and length at maturity. In general, they were caught at size smaller than their maturity size. The proportion of immature C. brevipinna, C. falciformis, C. sorrah and S. lewini to their total number recorded at the surveyed area during the study were about 87%, 50%, 80% and 65%, respectively. According to the length at maturity, females generally attained their maturity in larger size than males. Some factors contributing the catches in immature size and conservation status of those four species were also discussed
MACROALGAE DIVERSITY AND LIFE FORMS OF INTER-TIDAL ROCKY SHORES
A study on macroalgae diversity and life form was carried out at inter-tidal rocky shores of Similajau National Park, Bintulu, Sarawak. Thirty five species were identified in this study, of which 15 belong to the division Rhodophyta, 12 to the Chlorophyta and 8 to Phaeophyta. Fifteen species are new records to the Park. Irrespective of areas, macroalgae from the three divisions; Chlorophyta, Phaeophyta and Rhodophyta did not show any distinct zonation. There was high number of macroalgae species in rocky area related to the sandy area. The high representation of macroalgae from rocky area reflects the availability of stable substrate and microhabitats for the occurrence and diversity of macroalgae species. The sandy area lacks hard structure responsible for the relatively low diversity of macroalgae. Four types of macroalgae life forms were identified namely epilithic, epipelic, epizoic and epiphytic. The general distribution, occurrence and a list of the macroalgae is presented
BIODIVERSITY AND LENGTH FREQUENCIES OF SHARKS CAUGHT IN THE INDIAN OCEAN
Study on biodiversity and size structure of sharks in the Indian Ocean was conducted at several landing sites and fish markets, i.e. Pelabuhanratu (West Java), Cilacap (Central Java), Kedonganan (Bali) and Tanjung Luar (East Lombok ). Field observation was done from April 2001 to March 2006. The results showed that there were 86 species of sharks belonging to 16 families in the Indian Ocean. The sharks were dominated by family of Carcharhinidae and Squalidae with 24 and 23 species, respectively. A high diversity of sharks was found at Kedonganan-Bali (49 species), at Tanjung Luar (47 species), at Cilacap (32 species) and at Pelabuhanratu (27 species). Size of sharks landed at those landing sites varied in length, the length of Carcharhinus amblyrhynchos was between 90 cm and 170 cm TL, C. sorrah (55-155 cm), C. obscurus (205-295 cm) and P glauca was caught at length between 205-300 cm
PRELIMINARY EVIDENCE OF GROWTH INFLUENCE ON CARBON STABLE ISOTOPE COMPOSITION OF Undaria Pinnatifida
Cultured sporophytic thalli of Undaria pinnatifida were collected at different periods of the year from Okkirai Bay, northeastern Japan. 13C of the thalli collected in January was much higher than that of the thalli collected in March, and young thalli collected in March showed a tendency towards lower 13C values comparing with adult ones. U. pinnatifida thalli grew fast in January, while young thalli in March showed slow growth due to the light limitation caused by shading adult thalli. Therefore, the growth rate of thallus may relate to 13C. Ongoing studies aim to quantitatively describe this relation and to search similar results for other species
THE PHYLOGENETIC TREE OF Alexandrium Prorocentrum AND PSEUDO-NITZSCHIA OF HARMFUL AND TOXIC ALGAE IN VIETNAM COASTAL WATERS BASED ON SEQUENCES OF 18sRdna, Its1-5.8s-Its2 GENE FRAGMENTS AND SINGLE CELL -PER METHOD
Molecular biological techniques support the identification of microalgae of Vietnam. Prorocentrum, Alexandrium and Pseudo-nitzschia are main harmful and toxic microalgal genera found in Vietnam coastal waters. The results of morphology and nucleotide sequence analysis of 18S rDNA and ITS 1-5.8S-ITS2 gene obtained from genomic DNA have shown that the Prorocentrum sp. 3 (isolated from Cat Ba, Hai Phong on October, 2004), Alexandrium sp. 5 (collected on October, 2004) and Pseudo-nitzschia sp. G3 (colleted in Do Son, Hai Phong on December, 2005) belonging to Prorocentrum mexicanum (the homological percent of 99.9% with sequencing of P mexicanum in Genbank ofY16232, AY886763), A. minutum (99.8% - AJ535388, DQ168664) and Pseudo-nitzschia pungens (98.8% - AY544769, DQ166533), respectively. The obtained results indicated that the exceptional fresh samples, for Prorocentrum genus which may be preserved at 25% ethanol, 4% formaldehyde, 1% glutaraldehyde, while Alexandrium genus ó at 25% ethanol, and Pseudo-nitzschia genus - 4% formaldehyde and 1% glutaraldehyde for two weeks have not effected on their analysis of sequences generated by Single Cell PCR method. In these studied samples, the nucleotide sequences obtained from genomic DNA and Single-cell PCR methods were the same with the homological percent more than 99%. Application of this method to samples collected from Phu Quoc Island, southern part of Vietnam, in 27-29, June, 2006 showed that Prorocentrum mican and P sigmoisdes were found
EURYPEGASUS DRACONIS LINNAEUS, 1766 (GASTEROSTEIFORMES: PEGASIDAE); A NEW RECORD TO THE DERAWAN ISLANDS, INDONESIA
Three specimens of Eurypegasus draconis Linnaeus, 1766 were collected in seagrass beds of Samama Island, East Kalimantan, in June 2006. It was the first record of this uncommon species that widely distributes in Indian and Pacific waters. The species was characterized by 8-9 tail rings and a spine on the dorsal side of last tail ring
OCEANOGRAPHIC CHARACTERISTICS OF KLABAT BAY, BANGKA ISLAND, INDONESIA
The oceanographic characteristics of Klabat Bay in Bangka Island of Indonesia were investigated by using a series of temperature, salinity, turbidity, TSS (total suspended solid), transparency, DIN (Dissolved Inorganic Nitrogen), DIP (Dissolved Inorganic Phosphorus), DO (Dissolved Oxygen) and chlorophyll-a data in the wet season (Northwest Monsoon) and dry season (Southeast Monsoon) of 2003, respectively. The observation results show that the hydro-oceanographic characteristics of Klabat Bay in the inner part and the outer part of the bay were dominantly influenced by the terrestrial and oceanic environment, respectively. High precipitation during the wet season decreased salinity, DO and transparency and increased total suspended solid (TSS), turbidity, DIN and chlorophyll-a within the bay. The reverse occurred during the dry season, except DIP
MANGROVE IN THE COASTAL ZONE OF LAMPUNG BAY PROVINCE OF LAMPUNG: A PRELIMINARY STUDY
Study on mangrove forest in the coastal zone of Lampung Bay, Province of Lampung was carried out on March 12 — 30, 2007. The data was collected from 8 stations, (Pidada Bay, Limbungan, Puhawang Kecil Island, Kalangan, Klagian Island, Kapuran, Ringgung, and Hurun Bay) based on the transect method. The result showed that the mangrove in the coastal zone of Lampung Bay was dominated by Rhizophora apiculata. The floristic composition of mangrove in this area consisted of 31 species. Recently, the extent of mangrove in the coastal zone of Lampung Bay was decreasing due to conversion of mangrove into human settlement, fishpond, road, and uncontrolled mangrove exploitation. This situation leads to the depletion of the living organisms which inhabit this area