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The present study is the first investigation on ectoparasites of commercial important fish from Segara Anakan, a brackish water lagoon located at the southern coast of Java, Indonesia. Eight economically important marine fish species (Mugil cephalus, Siganus javus, Scatophagus argus, Caranx sexfasciatus, Lutjanus johnii, Eleutheronema tetradactylum, Johnius coitor, and Epinephelus coioides) were examined for crustacean parasites. Prevalence and intensity data for each parasite species are given, together with an analysis of the origin and possible transmission pathways. A highly divers copepod fauna consisting of 23 different species and two isopods was found. All fish species were at least infested with two copepod species, with the exception of L. johnii, S. argus, and M. cephalus. With seven and six species, respectively, they harboured the most species-rich ectoparasite fauna. The copepods Ergasilus sp. 3 and Caligus acanthopagri on S. argus showed the highest prevalence (78.6) and intensity [17.8 (1-233) and 5.3 (1-22)] of infestation. The recorded parasite fauna is represented by marine, brackish water, and probably also freshwater components. The brackish water environment of Segara Anakan does not prevent disease outbreaks due to parasitic copepods by preventing pathogenic marine or freshwater species to enter the lagoon. This might cause fish health problems if the Segara Anakan Lagoon would be developed for finfish mariculture in future.

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In order to decide which is the best growth model for the tambaqui Colossoma macropomum Cuvier, 1818, we utilized 249 and 256 length-at-age ring readings in otholiths and scales respectively, for the same sample of individuals. The Schnute model was utilized and it is concluded that the Von Bertalanffy model is the most adequate for these data, because it proved highly stable for the data set, and only slightly sensitive to the initial values of the estimated parameters. The phi values estimated from five different data sources presented a CV = 4.78%. The numerical discrepancies between these values are of not much concern due to the high negative correlation between k and Linfinity viz, so that when one of them increases, the other decreases and the final result in phi remains nearly unchanged.

Based on light and scanning electron microscopical studies, the following five species of the Philometridae (Nematoda: Dracunculoidea) are described from female specimens collected from marine fishes off the southwestern coast of Java, Indonesia: Philometra lobotidis sp. n. from the abdominal cavity of the Atlantic tripletail Lobotes surinamensis (Bloch) (lobotidae, Perciformes); Philometra javaensis sp. n. from the abdominal cavity of the immaculate puffer Arothron immaculatus (Bloch et schneider) (Tetraodontidae, Tetraodontiformes); Philometra psettoditis sp. n. from the musculature of the indian spiny turbot Psettodes erumei (Bloch et Schneider) (Psettodidae, Pleuronectiformes); Philometroides indonesiensis sp. n. from the musculature of the hound needlefish Tylosurus crocodilus crocodilus (Péron et Lesueur) (Belonidae, Beloniformes); and Philometroides trichiuri sp. n. from the dorsal fin of the largehead hairtail Trichiurus lepturus linnaeus (type host) and the savalai hairtail Lepturacanthus savala (Cuvier) (both Trichiuridae, Perciformes). All these new species are distinguished from their congeners parasitizing marine fishes by morphological (mainly the shape and structure of the cephalic and caudal ends and of the oesophagus) and biometrical features. Besides previously known Philometra pellucida (Jägerskiöld, 1893) and Philometra ocularis Moravec, ogawa, suzuki, Miyazaki et Donai, 2002, they are the only nominal philometrid species recorded from indonesian waters.

Bothriocephalidean cestodes reported from lizardfish (Saurida Valenciennes in Cuvier & Valenciennes) were revised on the basis of newly collected material from type-hosts and available typeand voucher specimens. Instead of nine taxa of four genera listed in the literature, only Oncodiscus sauridae Yamaguti, 1934 and Penetrocephalus ganapattii (Rao, 1954) are considered valid and thus both genera become monotypic. Both taxa are redescribed, including the first scanning electron micrographs and data on intraspecific variability. Both species are unique among bothriocephalid cestodes in the lateral position of the vagina in relation to the cirrus-sac. Oncodiscus sauridae found in Saurida longimanus Norman, S. nebulosa Valenciennes (new host record), S. tumbil (Bloch) and S. undosquamis (Richardson) differs from P. ganapattii found in S. micropectoralis Shindo & Yamanda and S. tumbil in the following characters: (i) scolex shape (fan-shaped, with crenulated bothrial margins in O. sauridae, replaced by a scolex deformatus in P. ganapattii); (ii) site of scolex attachment (in the intestinal lumen in the former taxon versus penetrating through the intestinal wall, and encysted on pyloric caeca in P. ganapattii); (iii) shape of segments (usually only slightly wider than long in O. sauridae versus very short, much wider than long in P. ganapattii); and (iv) number of testes (50–100 per segment in O. sauridae whereas fewer than 60 in P. ganapattii). Bothriocephalus sauridae Ariola, 1900 is considered a species inquirendum, although conspecificity with O. sauridae is very probable. The present study demonstrates the necessity of using standard procedures, especially adequate fixation methods of freshly collected cestode material (hot 4% formaldehyde solution is strongly recommended for morphological studies), because most previous descriptions were based on poor-quality material, including partly macerated worms missing hooklets on the apical disc of the scolex in O. sauridae.

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