Marine Research in Indonesia (MRI - E-Journal)
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CHEMICAL ECOLOGY OF SHALLOW WATER OCTOCORALS. OCCURRENCE OF CEMBRANOLIDES IN PSEUDOPLEXAURA AND EUNICEA
No full textGorgonians of the genus Pseudoplexaura, from a variety of geographical locations, yield crassin acetate as the major cembranolide. The cembranolides found in Eunicea collected at different locations vary. Eunicin is found in Eunicea mammosa from Bimini, and from a number of other locations. Its position isomer Jeunicin, has been found in the Eunicea from Jamaica. Eunicea from Curacao yields an epimer ot eunicin, Cueunicin, while that from Puerto Rico yields Eupalmerin acetate, and Peunicin occurs in Eunicea collected off Panama. The cembranolides are toxic to various aquatic organisms. They inhibit ciliary action in the ciliate Tetrahymena pyriformis, and in the larvae of the nudibranch Phestilla sibogae
PERICLIMENES DENTIDACTYLUS, A NEW DEEP WATER PONTONIINE SHRIMP FROM MAKASSAR STRAIT, INDONESIA
No full textA new species of pontoniine shrimp, Periclimenes dentidactylus is described and illustrated. The single specimen was collected from Makassar Strait from over 590 m, a depth exceeded by only two other species of the genus. P. dentidactylus is closely related to F. hertwigi Balss, and is probably also an echinoid associate
REVISION OF THE INDO-PACIFIC SPHENOCARCINUS WITH A SINGLE ROSTRUM AND DESCRIPTION OF TWO NEW SPECIES (CRUSTACEA, DECAPODA, BRACHYURA, MAJIDAE)
No full textTwo species of the genus Sphenocarcinus A. Milne Edwards 1876, with a single rostrum exist in the Indo-Pacific and they are principally only known by their original description: S. cuneus (Wood-Mason 1891) and S. aurorae Alcock 1899. Each species is herewith redescribed, based on the examination of the types. Two new species are established. S. difficilis sp. nov., represented by numerous specimens from Madagascar (ORSTOM collection), proved to be an intermediate species between S. cuneus and S. aurorae. S. pinocchio sp. nov., (collected in the Makassar Strait, Indonesia (mission Corindon II), is characterized by its very Jong and strongly curved rostrum. One male specimen, also collected in the Makassar Strait, probably modified by a sacculinid parasite, and with a more curved, snub rostrum, can be regarded as an unusual form of S. pinocchio sp. nov. A key of the four Indo-Pacific Sphenocarcinus with a single rostrum is presented
A CYCLONIC EDDY NORTH OF LOMBOK
No full textA satellite drifter that passed from south to north through Lombok Strait in early 1988 became trapped in a cyclonic eddy 100 km north of Lombok. The eddy, which was 130 km by 80 km, had a rotation period of 10 days
SPATIAL DISTRIBUTION OF TRACE METALS (Pb, Cr, Cu AND Zn) IN SEDIMENTS OF THE BERAU DELTA, EAST KALIMANTAN AND THEIR ACCUMULATION IN BENTHIC BIOTA
No full textBerau delta is a coastal ecosystem where man-made activities are relatively low. The present study has investigated spatial distribution of Pb, Cr, Cu and Zn in sediments and their implication to benthic biota. The result of our study showed that metal concentrations varied from undetected to 55.53 mg kg-1 for Pb and from 3.28 to 22.9 mg kg-1 for Cu, while for Cr and Zn vary from 9.65 to 64.67 mg kg-1 and 10.00 to 1,200 mg kg-1, respectively. The concentrations of Pb, Cu, Cr and Zn in Anadara sp were 7.53 ± 2.06, 4.92 ± 0.55, 1.44 ± 0.12 and 97.87 ± 9.12 mg kg-1 dry weight (dw), respectively. On the other hand, the Pb, Cr, Cu and Zn in Telescopium mauritsi were 4.49 ± 0.03, 0.87 ± 0.05, 259.0 ± 0.01 and 64.78 ± 0.01 mg kg-1 dw, respectively. In conclusion, spatial distribution of trace metals (Pb, Cu, Cr and Zn) in sediments showed that higher concentrations were found in the southern part of the delta, and the accumulation of the metals by mollusk might reflect natural concentrations in biota
PRELIMINARY OBSERVATION ON LIVING HABITS OF ACANTHASTER PLANCI (LINNAEUS) AT PULAU TIKUS, SERIBU ISLANDS
No full textDuring the period of June 1975 to August 1975, observations on living habit and some ecological aspects of Acanthaster planci were made at Pulau Tikus, Seribu Islands. The observations, limited to 8 metres deep, were made at the outer reef located south of Pulau Tikus, covering an area of about 4000 square metres. The density of living stony corals and the damaged caused by the feeding activities of A. planci were also studied. The results show that the average numbers of A. planci per month is 20 individuals per 4000 m2. The sizes of the starfish vary between 26-41 cm in diameter and the number of arms between 10 - 18. The moving distance of the starfish is 0.3 - 8 metres in 24 hours. The stony corals affected are Acropora squamosa (BROOK), A. spathulata (BROOK), A. Latistella (BROOK), A. quelchi (BROOK), Fungia sp.. Montipora ramosa BERNARD, Porites sp., DipIoria sp., and Goniatrea sp
PHYTOPLANKTON AND ZOOPLANKTON ABUNDANCE IN AMBON BAY
No full textAmbon Bay has a shallow neritic inner bay and a deep oceanic outer bay. Net hauls suggest the inner bay has a large population of large phytoplankton cells but a small population of macrozooplankton. In the outer bay the opposite situation exists, with a greater population of macrozooplankton and smaller population levels of small phytoplankton. The differences might be caused by nutrient pollution and siltation in the inner bay
EVIDENCE FOR TIDAL UPWELLING ACROSS THE SILL OF AMBON BAY
No full textTemperature observations across the sill of Ambon Bay in August 1982 and a model suggest that during the upwelling season of the south east monsoon tidal upwelling on the flood tide can suck thermocline water up the outer slope of the sill from a depth of 50 to 80 m. The water enters over the 10 m sill and replaces the bottom water in the inner part of Ambon Bay
EARTH SYSTEM PROCESSES OF THE WALLACEA AND THEIR IMPLICATIONS TO THE INDONESIAN THROUGHFLOW AND BIOGEOGRAPHY
No full textThe Wallacea with the total land area of 347,000 km designates a biogeographical group of Eastern Indonesian islands separated by deep water straits from the Asian and Australian continental shelves, and occupies a region with the world's most complex geological evolution and the accompanying extreme endemism. It also encloses remnants of emerged and submerged lands as well as dispersed and accreted island arcs and fragments of the continents resulting from a relatively continuous Cenozoic convergence of the Indo-Australian, Eurasia and Pacific-Philippine Sea plates. This paper discusses the Cenozoic spatial and temporal evolution of terranes in the region and explores how the Earth System Processes have eventually shaped up the Indonesian Throughflow and highlights the biogeographically unique and rich Wallacea. It will be demonstrated that the Wallace's line may have inherited an evolved multi-origin Early Cenozoic deep water barrier and the present Wallacea has been the resultant of significant Neogene convergent tectonics and significant modification by glacially-related sea level and climatic changes during the Quaternary. The gradual and systematic changes of the respective ocean regimes, the corresponding oceanometeorologic evolution, the emergence and disappearance of islands and land bridges, the dispersal and docking of some terranes have all resulted in the present configuration of the areas of endemism within the Wallacea. These changes correspond with the Neogene closure of the Indonesian Seaways, a narrow passage formed by the collision of the three major plates and the vanished pre-Cenozoic Tethyan ocean formed by the otherwise connected Indian and Pacific Oceans
FISSIPAROUS SEA CUCUMBER (Holothuria atra) POPULATION IN NORTH LOMBOK, INDONESIA
No full textSea cucumbers belonged to the species of Holothuria atra are one of the holothurians that could reproduce asexually through fission particularly when their ambient environments are not optimum to reproduce sexually. The reproductive pattern of H. atra has been shown to correlate with to the condition of H. atra population as well as their habitats and environments. This study aims to investigate the asexual reproduction and fission rate of H. atra in Tanjung, North Lombok, Indonesia. We conducted surveys in February, May, July, August, September and December 2016 by applying the free collection method. A total of 1,383 individual H. atra were collected consisting of 931 intact or normal individuals, 174 anterior individuals, 261 posterior individuals and 17 uncategorized individuals. Fissioned H. atra were found in every sampling conducted in the six different months with fission rates range from 5.53 to 30.40%. This research shows that the population of H. atra in Tanjung, North Lombok, are susceptible to asexual reproduction (fission). Fission rate value of > 5% is associated with an adaptation mechanism of H. atra to maintain their population in the wild. Further investigation on the environmental conditions stimulating H. atra fission is needed to understand the reproduction and population dynamic of this species in Tanjung waters