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Some aspects of the hydrographical conditions of the backwaters around Willington Island (Cochin)
Oceanographic Abstracts
1095
peculiar problems o f coral reefs are also discussed, such as the role of subsidence in the reef morphology, the relations between corals knolls and hydrological regime, and the differences between a barrier reef and a fringing reef. PoPE ELIZABETHC., 1965. A review o f Australian and some Indomalayan Chthamalidae (Crustacea: Cirripedia). Prec. Linnean Soc., New South Wales, 90 (407-I): 10-77. All species o f intertidal barnacles of the Family Chthamalidae known from Australian shores are reviewed and discussed with reference to their geographical distributions and ecological occurrence. Eight species in four genera are included but none is new to science. Considerable extensions of the ranges o f Chthamalus intertextus to New Guinea and o f Chthamalus malayensis, C. caudatus and C. withersi along the northern coast o f Australia are recorded. There are five tropical species in Australia in two genera, of which four are included in genus Chthamalus and one in Oetomeris. Only three species o f the family occur in the temperate southern half o f the continent, but each belongs to a different genus. Thus Catophragmus, Chthamalus and Chamaesipho are represented. A second species of Chamaesipho occurs in New Zealand, but these two species are the sole representatives o f the Family Chthamalidae in that region. Certain species of Chthamalus (C. withersi and C. caudatus) and Octomeris brunnea possess structures on their mouth parts and cirri which are believed to be adaptations for capturing particulate food over a relatively short period and in seas showing only slight to moderate degrees of water movement other than tidal flow except, o f course, during storms. The remaining five species from three genera have armouries of elaborate hooks or grapples well adapted to the holding of food particles, in the ebb a n d flow of surf or other considerable water movements. When these hooks, grapples and other food-holding adaptations are catalogued for each species, it will be found that the species constantly subjected to roughest water movements possess a greater variety of such adaptations than species from calmer situations. However, many more Chthamalid species will have to be examined before any conclusions about the phylogenetic significance of these structures, if any, can be drawn. RAMAMmTr~ C. P. and R. J^VARAMAN, 1963. Some aspects o f the hydrographical conditions o f the backwaters around Willington Island (Cochin). d. mar. biol. Ass., India, 5 (2): 170--177. The surface salinity of the backwater in Ernakulam channel has been studied for 5-yrs 1956--1960 and it is found that tidal influence on the salinity of the channel surface is practically nil. According to the trend o f surface salinity there appears to be three seasons in any year, a season of low salinity from June to September----October, a post monsoon season with upward trend in salinity from September---October to December--January characterised by rapid fluctuations in salinity values, and January to May when the channel contains water comparable in salinity to the inshore water. The results indicate the probability o f the presence of more saline and cooler water in the bottom region along the channel. RASMOSSm,~K. A. and N. E. ~ A D , 1965. The quiet gray whale (E~chrichtius glaucus). Deep-Sea
Res., 12 (6): 869-877. Studies conducted during the period December 22, 1964--March 7, 1965 near San Diego, California and at several locations in Baja California failed to confirm the use of acoustic signals by the gray whale. It is concluded that this cetacean rarely transmits subsurface sounds, and that it utilizes methods other than echolocation for navigation in shallower areas during the day. REID R. G. B., 1965. The structure and function of the stomach in bivalve molluscs, or. Zool., 147 (2): 156-184. The strncture and function o f the stomachs of nine bivalves are examined. These animals belong to the Gastrotetartika, Gastrotriteia, and Gastropempta, the three orders of the Polysyringia, a new subclass of the Bivalvia suggested by Purchon (1960a). It is found that in all three orders there are comm o n ciliary tracts and grooves. For example, tracts are always found in association with the duct openings, and a distinction between the right duct tract and the posterior sorting area is drawn. Another tract which is a constant feature of these stomachs, but which has not been noted before, is the antero-dorsal tract. A generalized polysyringian stomach is constructed. All the stomachs examined function similarly, there being set up in the lumina circulating currents of the gastric fluid. In general, large particles and masses of particles are recirculated until they are broken down, and small heavy particles are rejected by the sorting areas, o f which three main types are described. Light particles in suspension in the stomach fluid are carried by the circulating current to the vicinity o f the opening of the ducts o f the digestive diverticula. The form o f the primitive polysyringian stomach and the evolution of sorting areas are postulated. Possible steps in the evolution o f the gastropemptan stomach through the gastrotetartikan form are suggested. The function o f the appendix is that of a temporary store for large, heavy particles which escape the paUial sorting mechanisms. It is noted that this organ occurs in all three orders of the Polysyringia.
1095
peculiar problems o f coral reefs are also discussed, such as the role of subsidence in the reef morphology, the relations between corals knolls and hydrological regime, and the differences between a barrier reef and a fringing reef. PoPE ELIZABETHC., 1965. A review o f Australian and some Indomalayan Chthamalidae (Crustacea: Cirripedia). Prec. Linnean Soc., New South Wales, 90 (407-I): 10-77. All species o f intertidal barnacles of the Family Chthamalidae known from Australian shores are reviewed and discussed with reference to their geographical distributions and ecological occurrence. Eight species in four genera are included but none is new to science. Considerable extensions of the ranges o f Chthamalus intertextus to New Guinea and o f Chthamalus malayensis, C. caudatus and C. withersi along the northern coast o f Australia are recorded. There are five tropical species in Australia in two genera, of which four are included in genus Chthamalus and one in Oetomeris. Only three species o f the family occur in the temperate southern half o f the continent, but each belongs to a different genus. Thus Catophragmus, Chthamalus and Chamaesipho are represented. A second species of Chamaesipho occurs in New Zealand, but these two species are the sole representatives o f the Family Chthamalidae in that region. Certain species of Chthamalus (C. withersi and C. caudatus) and Octomeris brunnea possess structures on their mouth parts and cirri which are believed to be adaptations for capturing particulate food over a relatively short period and in seas showing only slight to moderate degrees of water movement other than tidal flow except, o f course, during storms. The remaining five species from three genera have armouries of elaborate hooks or grapples well adapted to the holding of food particles, in the ebb a n d flow of surf or other considerable water movements. When these hooks, grapples and other food-holding adaptations are catalogued for each species, it will be found that the species constantly subjected to roughest water movements possess a greater variety of such adaptations than species from calmer situations. However, many more Chthamalid species will have to be examined before any conclusions about the phylogenetic significance of these structures, if any, can be drawn. RAMAMmTr~ C. P. and R. J^VARAMAN, 1963. Some aspects o f the hydrographical conditions o f the backwaters around Willington Island (Cochin). d. mar. biol. Ass., India, 5 (2): 170--177. The surface salinity of the backwater in Ernakulam channel has been studied for 5-yrs 1956--1960 and it is found that tidal influence on the salinity of the channel surface is practically nil. According to the trend o f surface salinity there appears to be three seasons in any year, a season of low salinity from June to September----October, a post monsoon season with upward trend in salinity from September---October to December--January characterised by rapid fluctuations in salinity values, and January to May when the channel contains water comparable in salinity to the inshore water. The results indicate the probability o f the presence of more saline and cooler water in the bottom region along the channel. RASMOSSm,~K. A. and N. E. ~ A D , 1965. The quiet gray whale (E~chrichtius glaucus). Deep-Sea
Res., 12 (6): 869-877. Studies conducted during the period December 22, 1964--March 7, 1965 near San Diego, California and at several locations in Baja California failed to confirm the use of acoustic signals by the gray whale. It is concluded that this cetacean rarely transmits subsurface sounds, and that it utilizes methods other than echolocation for navigation in shallower areas during the day. REID R. G. B., 1965. The structure and function of the stomach in bivalve molluscs, or. Zool., 147 (2): 156-184. The strncture and function o f the stomachs of nine bivalves are examined. These animals belong to the Gastrotetartika, Gastrotriteia, and Gastropempta, the three orders of the Polysyringia, a new subclass of the Bivalvia suggested by Purchon (1960a). It is found that in all three orders there are comm o n ciliary tracts and grooves. For example, tracts are always found in association with the duct openings, and a distinction between the right duct tract and the posterior sorting area is drawn. Another tract which is a constant feature of these stomachs, but which has not been noted before, is the antero-dorsal tract. A generalized polysyringian stomach is constructed. All the stomachs examined function similarly, there being set up in the lumina circulating currents of the gastric fluid. In general, large particles and masses of particles are recirculated until they are broken down, and small heavy particles are rejected by the sorting areas, o f which three main types are described. Light particles in suspension in the stomach fluid are carried by the circulating current to the vicinity o f the opening of the ducts o f the digestive diverticula. The form o f the primitive polysyringian stomach and the evolution of sorting areas are postulated. Possible steps in the evolution o f the gastropemptan stomach through the gastrotetartikan form are suggested. The function o f the appendix is that of a temporary store for large, heavy particles which escape the paUial sorting mechanisms. It is noted that this organ occurs in all three orders of the Polysyringia.