Two new species ofHalicyclops (Copepoda,Cyclopoida) from the Amazon Basin,Brazil

Two new species ofHalicyclops are described from plankton samples taken in two localities in the Amazon River mouth area, State of Pará, Brazil.Halicyclops lindbergi sp.n. resemblesH. hurlberti andH. clarkei from which it differs by a combination of characters in leg 5, the anal pseudoperculum and the caudal rami. The other new species,H. dussarti, is most morphologically similar toH. pilosus, but they are separated by differences in legs 1 and 5 as well as in the ornamentation of the middle caudal setae.     

Occurrence of limnic micro-crustaceans in relation to temperature and oxygen

Information on the distribution of 56 micro-crustaceans from different types of waters in south and central Sweden was analyzed to reveal their relationships to temperature and oxygen content. A very wide tolerance range concerning these factors was found for most species.     

A revision of Thompsonulidae Lang, 1944 (Gopepoda: Harpacticoida)

The harpacticoid copepod subfamily Thompsonulinae Lang, 1944, formerly recognized as belonging to the family Tachidiidae (Lang, 1948) is raised to family rank and redefined to include only the genera Thompsonula T. Scott and Caribbula gen. nov. Thompsonula hyaenae (I. C. Thompson) and T. curticauda (Wilson) are redescribed and refigured. Re-examination of the original material showed that Wilson's Rathbunula agilis is synonymous with T. curticauda and not with T. hyaenae , as suggested by Lang (1948). It is now clear that the two species of Thompsonula have distinct distributions, T. curticauda being confined to the North American continent and T. hyaenae to western Europe and the Mediterranean. The genus Caribbula is established to accommodate the type species, T. hyaenae elongata (Gee) and C. fleegeri sp. nov. which are described and figured. The genus Caribbula is distinguished from Thompsonua , primarily by the unique sexual dimorphism on the exopod of P4 and, at present, is known only from the eastern seaboard of the United States and Gulf of Mexico. The genera Danielssenia, Psammis, Paradanielssenia, Micropsammis and Leptotachidia are tentatively assigned to the family Paranannopidae Por.     

Lipid storage in Diaptomus kenai (Copepoda; Calanoida): effects of inter- and intraspecific variation in food quality

In nature, changes in nutrient levels and phytoplankton community structure can represent variation in food quality and quantity. Because zooplankton can be highly susceptible to starvation, individuals could enhance their survival, growth, and reproduction during periods of unfavorable food conditions by maintaining and utilizing energy stores. Patterns of lipid accumulation and depletion in Diaptomus kenai, a calanoid copepod from an oligotrophic montane lake, were monitored over a variety of food conditions. The results suggest that, while lipid storage in D. kenai is affected by phytoplankton community structure and abundance, total lipid stores respond more to gradual changes in food regime than to sudden changes in food supply.     

Ostrincola koe (Copepoda,Myicolidae) and mass mortality of cultured hard clam (Meretrix meretrix) in China

We discuss the primary cause of mass mortalities of cultured hard clam (Meretrix meretrix) which occurred in 1988 and 1989 in southern Jiansu, China. Based on a re-examination of the old samples and analysis of information from Japan and Korea, it is concluded that the population explosion of the parasitic copepod, Ostrincola koe Tanaka, in the clam mantle cavity, combined with an acute vibriosis in the intestine, were responsible for the mass mortality. Other incidences of hard clam mass mortalities in China, Korea and Taiwan in the 1970s and 1980s are also discussed.     

Latitudinal diversity patterns of continental benthic copepod species assemblages in the Americas

The diversity, considered as richness (numbers) of genera and species, of continental benthic Copepoda of the Americas was examined. Thirty-three local lists of planktonic and benthic Cyclopidae (Eucyclopinae and Cyclopinae), 21 local lists of epibenthic Harpacticoida (Canthocamptidae), and 8 local lists of interstitial Harpacticoida (Parastenocarididae) were compared. Available data do not allow the rejection of the null hypothesis of no significant difference in diversity of tropical and temperate copepod faunas. For Cyclopidae, 6–15 genera and 6–44 species were recorded from local areas; linear regression analysis showed no significant correlation between latitude and number of genera and species. For Canthocamptidae, 1–13 genera and 3–43 species were recorded locally, with no significant correlation between latitude and number of species; for genera the correlation between latitude and number of genera was strongly positive, but the effect of latitude is small. No relationship between latitude and diversity of the Parastenocarididae was evident from inspection. Endemism of Cyclopidae and Canthocamptidae is significantly greater in South America, as shown by comparisons of Sørensen's similarity coefficient between paired areas. Because of this high degree of endemism, conservation strategies for South American wetland invertebrates should emphasize preservation of many small sites.     

Three new genera and five new species of misophrioid copepods (Crustacea) from anchialine caves on Indo-West Pacific and North Atlantic Islands

Hydra lirosoma sp. nov. is a small, hermaphroditic species possessing broad holotrichous isorhiza nematocysts. The spherical embryo and cobbled embryotheca set it apart from similar species. Hydras with broad holotrichous isorhizas form a distinct cluster of species, but one which was not explicitly represented in the three genera ( Pelmatohydra, Hydra and Chlorohydra ) recognized by Schulze (1917, Archiv für Biontologie, 4(2 ): 29). Schulze failed to recognize this group because of the small number of species known at that time. The hydras that are known now fit naturally into four clusters of species termed, in this paper, the oligactis, vulgaris, viridissima, and braueri groups.     

New or rare species of Diacyclops Kiefer, 1927 (Copepoda,Cyclopoida) from different groundwater habitats in Italy

Diacyclops paralanguidoides sp.n., Diacyclops paolae sp.n., Diacyclops maggii sp.n. and Diacyclops sardous sp.n., all belonging to the languidoides-group of species, are described from groundwaters (wells, hyporheic habitats) in Italy.New localities are reported, from the same country, for other remarkable species of the genus, viz. Diacyclops clandestinus (Kiefer) and Diacyclops zschokkei (Graeter).The absence of a vestigial exopod and the armature of the basipodite of the antenna are considered as useful diagnostic characters for species demarcations.Research supported by a M.P.I. 60% grant. Gruppo Nazionale C.N.R.-Biologia Naturalistica.Contribution to the knowledge of the underground water fauna in central and southern Italy: XXXVIII.     

Recording the beat patterns of the second antennae of calanoid copepods,with a micro-impedance technique

A device utilizing the suction produced by a plastic syringe, has been developed to restrain copepods in flowing seawater, allowing close observation of the experimental animal. Direct records of appendage movements can be achieved by using an electrode technique based on the impedance pneumograph, and the temporal activity patterns of such limbs can be displayed on a chart recorder. These methods have been applied to six species of marine calanoid copepods to record antennal beat patterns, and appendage movements during the escape response.