ALBERT

Description: Three species of Foraminifera, which were ususally regarded as members of the Ammonia beccarii (L.)-group or closely related, are investigated. The material comes mainly from the lagoon of Cochin and from the shelf off Cochin (SW-India), Malabarcoast). Sections and Stereoscan-microphotographs revealed considerable differences in the internal structure (double or simple septae, different shape of the tooth-plates, areal or interiomarginal situation of the septal apertures). This leads to the conclusion, that only one species (Rotalia beccarii var. sobrina SHUPACK 1934) is a true Ammonia. Rotalia beccarii var. tepida CUSHMAN 1926 should be put to the genus Discorbis, Rotalia pauciloculata PHLEGER & PARKER 1951 is regarded as a species of Pseudoeponides. Some ecological observations are added.

Description: Shipworms or Teredinidae may be dispersed either as adults in floating wooden objects or as pelagic larvae drifting near the sea surface. Five shipworm species, i.e., half of those having an amphi-Atlantic geographical distribution, are known also to have pelagic phytoplanktotrophic larvae which can be carried by ocean currents. From a series of 742 plankton samples taken from throughout the temperate and tropical North Atlantic Ocean, it can be shown that shipworm larvae are not uncommon in the open sea. Teredinid veligers were found in 19% of all samples taken. One species of larvae, identical in all details to that described by Rancurel (1965), is particularly prevalent and is tentatively identified as Teredora malleolus (Turton). A definitive identification will be possible only after the pelagic larvae of the other Atlantic species are known. The larvae of Teredora malleolus are found throughout the North Atlantic Gyre and the adjacent temperate and tropical seas, and from scattered records in the South Equatorial Current. Larvae of other unidentified Teredinidae species were also found. The distance that larvae may be transported depends upon the length of pelagic larval development and the velocity of the currents. From the known current velocities it can be shown that, even in a few weeks, larvae may be dispersed many hundreds of kilometers. The geographical distribution of shipworm larvae suggests that they are carried along the coasts of continents and even across ocean basins, and that this dispersal must be an important factor in the geographical distribution of the adult forms and in the maintenance of genetic continuity between populations otherwise isolated from one another.

Description: A technique for rearing the loliginid squids Sepioteuthis sepioidea and Doryteuthis plei is reported. Specimens of the former were reared from eggs to sexually mature adults, and maintained for a maximum of 146 days; adult D. plei were maintained for 38 days. Choice and quantity of food was most important for the survival of all sizes, particularly young squid. Newly hatched specimens thrived on Mysidium columbiae. Both species fed at a rate of 30 to 60% of their body weight daily; starvation occurred when intake fell below 10 to 15%. Food conversion efficiency averaged between 10 to 20%. Growth was rapid and steady. S. sepioidea grew to a maximum of 105 mm and 77 g in less than 5 months; D. plei grew an estimated 20 mm/month. Experimental data indicate a lethal minimum salinity for both species at about 27‰. Lethal minimum and maximum temperatures for young S. sepioidea are 17.5° to 18.0°C, and 32.5° to 33.0°C, respectively. Young consume 0.64μl O2/mg wet weight/h. Opaque tanks, with a semi-natural bottom substrate and special ultra-violet (UV) illumination, are advantageous for rearing and maintenance.

Description: Analyses of bottom trawl samples and feeding experiments in the laboratory revealed a reproduction period ranging from late March to early August in Eledone cirrosa of the Catalonian Sea (Western Mediterranean). The embryonic development, studied for the first time on eggs laid in the laboratory, shows no basic difference from that of other Octopodiae. The newly hatched animals are planctonic; Morphologically, this feature is expressed by a relatively small arm-length.

Description: Five species of Sepiola were reared in the laboratory from egg to adult size. Spawning was achieved in 3 species of Sepiola afteer 5 to 7 months. The growth rate of the species reared did not depend upon temperature, which ranged from 12,5° to 20°C. A fairly constant size increase (2,5mm mantle length/month) was observed in Sepiola during the 5 months after hatching. In Sepietta, the same growth rate was observed until the fourth month after hatching, when it increased to the rate of 5 mm mantle length/month.