The Leiognathus splendens complex (Perciformes: Leiognathidae) with the description of a new species, Leiognathus kupanensis Kimura and Peristiwady

Taxonomic analysis of a group of morphologically similar ponyfishes (Perciformes: Leiognathidae) establishes the Leiognathus splendens complex comprising four valid species: L. jonesi James, 1971, widely distributed in the Indo-West Pacific, from Mauritius to Papua New Guinea, north to Hainan I. (China), and south to Brisbane, Australia; L. kupanensis sp. nov., currently known only from Kupang, Timor, Indonesia; L. rapsoni Munro, 1964, currently known only from India, Indonesia, and Papua New Guinea, and L. splendens Cuvier, 1829, widely distributed in the eastern Indian and western Pacific oceans, from India to Papua New Guinea, and from southern Japan to northern Australia. The L. splendens complex can be defined by the following combination of characters: body depth 42–60% of standard length; mouth protruding downward; slender, minute teeth uniserially on jaws; lower margin of orbit above the horizontal through the gape when mouth closed; breast almost completely scaled; lateral line complete, and a dark blotch on top of spinous dorsal fin. Diagnostic characters of the members are as follows: L. jonesi —anterior dorsolateral body surface with a semicircular naked area on nape, and a paler dark blotch on spinous dorsal fin; L. kupanensis —anterior dorsolateral body surface widely naked; L. rapsoni —cheek scaled; L. splendens —anterior dorsolateral body surface completely scaled and a jet black blotch on spinous dorsal fin.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41595/1/10228_2005_Article_283.pd

In-situ studies in the echinoderm Asterias rubens as a predator of soft-bottom communities in the western Baltic Sea

In-situ investigations on the life of the common sea star (Asterias rubens L.) were carried out in 1976, employing the Underwater Laboratory 'Helgoland' in Lübeck Bay (Western Baltic Sea). The abundance of A. rubens amounted to 2-31 m SUP--2 on sediment (fine sand), and to 324-809 m SUP--2 on mobile algal carpets drifting over the bottom. Actual population parameters (abundance, size class distribution) areinfluenced by both substrate quality and drifting. Stomach investigations revealed prey-size selectivity: small sea stars feed mainly on the snail Hydrobia ulvae when living on the sediment, but on mussel brood (Mytilus edulis) in the phytal. The principal food items of larger sea stars are the sand-dwelling clam Macoma baltica and the phytal-living isopod Idotea baltica respectively. A.rubens is very adaptive to the food availability; the diversity of its diet corresponds to the species diversity found in its environment. A change of biotope during active or passive migrations causes switching. The sea star is able to catch motile animals and to dig outinfaunal clams. It exhibits a diurnal feeding pattern related to light periodicity; the activity decreases at night. The average frequency of feeding is highly dependent on predator body size; it declines with growth. In situ-experiments indicate an exponential relationship between the feeding duration upon M. baltica and the quotient of clam size to logarithm of sea-star size. An approach is made toward a rough estimate of macrofauna consumption by A. rubens on sediment. The sea star seems to be an important predator and thus a competitor of demersal fishes on soft bottoms of the western Baltic Sea