The Crown-of-Thorns starfish Acanthaster planci (Linne') in Ceylon

The Crown-of-Thorns starfish Acanthaster planci is a predator of coral and has been responsible for the widespread destruction of coral reefs. In Sri Lanka this starfish was first reported by Clarke in 1915. Recently skin-divers reported that Acanthaster planci was present in very large numbers in the coastal waters off Trincomalee, especially on the coral formations around Pigeon Island. It is well known that the multiplication of the starfish to plague proportions is a serious threat to the coral reef formations round the Island. If it were allowed to continue its depredations the entire coral reef belt round the Island might be destroyed in a short time. The monsoon waves would then convert the dead coral to rubble. In the absence of a barrier against the advancing waves during the monsoon it would also lead to serious erosion of the shoreline. The coral reef fish would also disappear with the destruction of the coral formations. On account of these considerations it was decided to conduct a survey of the Crown-of-Thorns starfish in eastern coastal waters in order to estimate the magnitude of the population of the starfish in these waters.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 1. Preliminary report: introduction and description of the stations

The Austrian-Ceylonese hydrobiological mission of 1970 investigated and made collections from 36 flowing water systems (brooks, torrents, rivers); of these, 34 water systems were in the mountains regions of south-west and south-east of Sri Lanka. In the crystalline mountain region, the water systems are extremely poor in electrolytes, very soft and slightly acid; these torrential streams have strong falls, high flow velocities and boulder bottoms. The water temperatures increase from the sources and brooks at 2,000 m altitude to the mouths from 15°C to 28°C. The density of animal population (macro and meso-fauna) increases from the river bank regions (and pools) towards the sections with strong current and reaches on the rocks in the cascades a density of 500 to appr. 750 individuals/1/16m².

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 2. Hydrochemical studies on mountain rivers in Ceylon

The morphology, climate, geology and geochemistry of Sri Lanka is briefly described. The separation into a wet zone (the south-west and greater part of the central highland) and a dry zone with two very dry parts in the south-east and in the north-west, is obvious and has great influence on the hydrochemistry of the island. Geology is very homogenous (Precambrian crystalline series) and some Jurassic and Miocene limestones (only in the north).

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 3. Uber einige wassermilben aus Ceylon (Hydrachnellae, Acari)

In the study are described five species of watermites, collected by the Austrian-Ceylonese hydrobiological mission 1970 in torrents of the highlands of south-west Sri Lanka. The species are: Torrenticola (Monatractides) pusta Cook, 1967, T.(M.) Oxystoma hamata (Lundbald, 1941), T.(M.) ceylonensis nov. spec., Atractides schwoerbeli Lundbald, 1969 and Arrenurus (Micruracarus) madaraszi Daday, 1898.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 4. List of reptilia and amphibia collected in the mountains of south-west Ceylon, with notes on finding localities

Sri Lanka is a comparatively small island (65.584 km²) within the equatorial belt of calms. There are only slight seasonal variations in temperature, air humidity and day length. A description is given of the amphibian and reptile material brought back from the Austrian Indo-Pacific expedition, 1970-71. Some notes on the habitat of the animals are included.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 5. Decapoda Caridea

The first comprehensive study on the freshwater Caridea of Sri Lanka was by Arudpragrasm and Costa in 1961. Although it was the intention of these authors to continue this study no opportunity was available to them. The present faunal survey however has afforded the present writer to make a detailed study of the distribution of these shrimps especially in the mountain streams of the south-west of Sri Lanka. Two species and two sub-species of Caridina, one species of Atya and four species of Macrobrachium were collected by the hydrobiological mission from the hill streams of Sri Lanka.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 6. A new Drepanosticta from Ceylon (Order: Odonata; insecta)

The author describe a new species of Drepanosticta from Sri Lanka. This new species is named in honour of the collector, Professor Dr. F. Starmühlner.

Fluctuations in species composition of Penaeid prawns in estuaries

During a study of the distribution of penaeid prawns in Sri Lanka waters a difference was noticed in the species composition from one estuary to another. Moreover, a marked monthly fluctuation in the relative abundance of the different penaied species was also observed. This indicated migratory behaviour. In order to study this phenomenon in the different species of prawns, regular samples of prawns were collected from two estuaries on the south-west coast of Sri Lanka, namely at Moratuwa/Panadura and at Negombo. The investigation was spread over a period of three years from 1957-1959.

Chemical analyses of some Ceylon fishes - 3

Chemical analyses of fishes found in Sri Lanka were initiated by Lantz and Gunasekera (1957), who presented data from examination of 30 different species of fishes. Later Peiris and Grero (1972) published the analysed data of 5 more species. The present paper continues the analyses and the results obtained from 10 more varieties of marine fishes are given.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 7. Dryopidae and Elminthidae of Ceylon

This report comprises a summary of parasitic copepods from fishes in Ceylon, as isolated from the branchial material of fishes belonging to previous collections. Seven copepod species are described in detail, as well as one species of Branchiura and one species of Isopoda. Caution is advocated to avoid further introductions via parasite-infested fishes, since only four of the above species are endemic.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 9. Dytiscidae (Coleoptera)

The intensive collecting of Prof. Dr. F. Starmühlner and Prof. Dr. H. H. Costa in Ceylon in 1970 produced among others some Dysticidae. The material turned out to be especially interesting as it comes all together from running waters, in which otherwise collecting is infrequent. From Sri Lanka quite a lot of species of Dytiscidae are already known.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 10. Freshwater triclads (Turbellaria, Tricladida) from Ceylon

The collection of Triclads from the Austrian-Ceylonese hydrobiological mission originates from 23 streams in the mountains of the south of Sri Lanka. All collected animals are of the Dugesia gonocephala (Dug.) type. Unfortunately the determinable mature animals were very rare in the samples but it seems certain that all the Triclads, found by the mission, belong to Dugesia nannophallus, described by Ball in 1970 after two individuals from Dunhinda, Badulla (Prov. Uva, Sri Lanka).

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara Campus of the University of Ceylon. Pt. 11. Larvae and pupae of water beetles collected from the islands of Ceylon

Water beetle larvae and pupae were collected from the lotic biotopes in localities of the southern part of Ceylon. The species are described and findings are related to previous investigations. The following families were represented: Dytiscidae, Gyrinidae, Hydrophilidae, Helodidae, Dascillidae (Eubrianacinae), Dryopidae and Lampyridae.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the University of Ceylon Vidyalankara Campus, Kelaniya. Pt. 12. Contributions to the ecology of the larvae of some Odonata from Ceylon

The Austrian-Ceylonese hydrobiological mission studied 38 biotopes; 28 of which contain Odonata. From the Zygoptera the Calopterydoidea seem to be the dominant form (22 habitats), while the Coenagrionoidea are scarcer (11 habitats). The most frequent species was Euphaea splendens (Epallagidae - 16 habitats) followed by Vestolis apicalis nigrescens (Calopterygidae, 8 habitats) and Neurobasis chinensis (Calopterygidae, 6 habitats). From the Anisoptera Zygonyx ceylanica (Libellulidae: Zygonictinae) was the dominant form (8 habitats), but some Libellulinae remain undescribed. The number of species varied greatly between different biotopes. The biotopes containing Odonata are small brooks, in which the pH was mostly on the limit between acid and alkaline reaction. They are fast running waters, situated in most cases on lower or middle elevations, only three species being found in higher elevations (1800-2000 m). Adaptations to fast currents and other factors are described.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the University of Ceylon Vidyalankara Campus, Kelaniya. Pt. 13. Some remarkable ripicol insects of the Ceylonese fauna

New Ceylonese records namely, Euscelimena gavialis (Sauss.), Paranemobius pictus Sauss. and semiaquatic cockroaches of the genus Rhabdoblatta were found in the collection of Saltatorid and Dictyopterid insects.