近亲裸腹溞对海水盐度的适应性

为了解淡水枝角类对海水盐度的适应性,在实验室内采用种群实验生态学方法研究25 ℃±0.5 ℃恒温条件下不同盐度（0、1、2、3、4、5）对近亲裸腹溞(Moina affinis)生存、生长和生殖的影响.结果表明,在各盐度梯度范围内,近亲裸腹溞的平均寿命随盐度升高而缩短,盐度4和5组内禀增长率与其它各组差异显著;盐度4和5组平均每窝产幼量与对照及其他组差异显著.一生产幼量除盐度1组和对照组较高外,其他各组均显著下降.对照组体长增长幅度与日增长率均低于各处理组.日增长率随着盐度的升高而增大.个体平均每胎产幼量以盐度1、2组最高.盐度5为近亲裸腹溞的生存和生殖盐限,但经过短期的海水驯化,其生殖耐盐上限有所提升,可达6.5.     

Two new species of Diaphanosoma Fischer, 1850(Crustacea: Branchiopoda: Cladocera) from the United States

Two new species of the genus Diaphanosoma, D. oligosetum and D. dorotheae, from Louisiana and North Carolina respectively, are described. The former species has large head with protruding dorsal part, large lanceolate spine on the basipodite's distal outer end, an extremely reduced number of antennal setae, up to six in adult specimens, and unique armament of valve margin. On the whole, it shows the pronounced combination of primitive and specialized morphological traits. D. dorotheae is a member of D. brachyurum species group differing from its other known representatives in presence of a small but very conspicuous spine on the end of proximal segment of antennal exopodite and a variable number of setae (seven or eight) on the distal segment of the branch. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Ilyocryptus thailandensis sp. nov. (Cladocera: Anomopoda: Ilyocryptidae) from North Thailand

Previously only a single species of Ilyocryptus Sars , 1862 (Cladocera: Anomopoda: Ilyocryptidae) was reported from Thailand, I. spinifer Herrick , 1882. However, our examination of numerous samples from this country resulted in the discovery of four other species of Ilyocryptus. Ilyocryptus thailandensis sp. nov. is described from two adjacent water bodies in Uttaradit Province, North Thailand. It has at least two characters which distinguish it from any other species of the Ilyocryptus: (1) a row of lateral setae reaching medial anus, and continuing along preanal margin up to base of the postabdomen; (2) a large projection bearing the sensory setae, situated on the coxal region of antenna II. It appears to be a rare species, may be, endemic of the North Thailand.     

Moina ephemeralis n.sp. from Central Europe

Moina ephemeralis n.sp. is described from SouthSlovakia. It belongs to the Moinagouldeni-lipini group. Together with Moinamacrocopa (Straus, 1820) it is the second specieswith a 2-egged ephippium from Central Europe. Thespecies was recorded in the plankton of a highlyeutrophic fish pond.     

The Biogeography of Cladocera (Crustacea) in Tropical Australia

Ninetysix species of Cladocera, comprising 8 Sididae, 50 Chydoridae, 17 Macrothricidae, 5 Moinidae, 2 Bosminidae, and 14 Daphniidae, occur in tropical Australia. Of this number 38% are cosmopolitan including so-called cosmopolitan species, 13.5% are circumtropical, 13.5% occur as well innear by countries, and 35% are endemic. North Queensland is a major area of speciation. Species richness varies from north to south and from wetter coastal areas to the drier inland. Major factors influencing richness and distribution are the relative proportion of floodplain billabongs in an area, coupled with rainfall reliability. The most common species include Alonella clathratula, Chydorus nr. pubsecens, Macrothrix triserialis, Oxyurella singalensis, Ephemeroporus nr. barroisi, Dadaya macrops, Diaphanosoma sarsi, Ceriodaphnia cornuta, and Dunhevedia crassa.     

Cladocera (Crustacea) from Nicaragua

Thirty-one Cladocera taxa are recorded from lakes, rivers and ponds of Western Nicaragua. They include Alona bromelicola sp. nov. found in water accumulations in epiphytic Bromeliads. The Cladocera recorded are neotropical and circumtropical. Other invertebrates found are also listed.     

Moina oryzae n. sp. (Cladocera,Moinidae) from Tamil Nadu (South India)

Moina oryzae n. sp., from a rice field in South India, is described. The species is related toMoina reticulata Daday, 1905, and toMoina minuta Hansen, 1899. The parthenogenetic and sexual females and male are described. A differential diagnosis is given.     

Revision of the Genus BosminaBAIRD, 1845 (Crustacea,Cladocera)

The genus Bosmina can be differentiated into four subgenera: 1. Bosmina s. str. BAIRD , 1845, 2. Eubosmina SELIGO , 1900, 3. Neobosmina LIEDER , 1957, and 4. Sinobosmina LIEDER , 1957. Subgeneric discrimination is based upon several features of the females (postabdominal claw, serration of the mucro, patterns of the lateral head pores) and, mainly, upon certain differences in the morphology of the male (postabdomen and, according to LILLJEBORG 1900, BURCKHARDT 1924 and KOŘINEK 1971, the first leg). The distribution of the Bosmina subgenera throughout the world varies: Bosmina s. str. is distributed worldwide (except for Australia?), Eubosmina is holarctic, Neobosmina has been found in Africa, the neotropical zone, Australia and Oceania, and Sinobosmina occurs in East and South-East Asia.     

Alona hercegovinae n. sp. (Cladocera: Chydoridae), a blind cave-inhabiting Cladoceran from Hercegovina (Yugoslavia)

Two interesting chydorid Cladocera were found in caves of Hercegovina and are described here. The pantropical Alona diaphana King, 1853 was already known in this part of Europe, but was found in a cave environment for the first time. Alona hercegovinae n. sp. is an eyeless and stygobiontic species, and was found in three caves.     

Description of Antichthomysis notidana n.g. n.sp. from southern Tasmania. (Crustacea: Mysidacea: Leptomysini)

Antichthomysis notidana n.g. n. sp. belonging to the Tribe Leptomysini is described from the coastal waters of south-eastern Tasmania. The genus is at present monospecific.     

Moina weismanni Ishikawa, 1896 (Cladocera,Moinidae) in Central Europe

Moina weismanni Ishikawa is reported from Czechoslovakia, Hungary, and Yugoslavia. The species was formerly synonymized with Moina micrura Kurz, based on parthenogenotic females. In both species, parthenogenetic females have a characteristic postabdomen, antennules (characters formerly regarded as typical for a variety of M. micrura), and ephippium. Wales are quite different. Examined populations of both species are similar in length-to-width ratio. M. weismanni is typical for small, eutrophic but permanent, and for large temporary water bodies. M. micrura is restricted to the plankton.     

New semi-terrestrial chydorids from the tropical rainforest of southwest Cameroon (Africa): Nicsmirnovius camerounensis n.gen. n.sp. and Bryospilus africanus n.sp (Crustacea: Anomopoda)

Two new chydorids, Nicsmirnovius camerounensis (gen. nov., sp. nov.) and Bryospilus africanus n.sp. are described, based on material from Korup, Mundemba, Bakingili and Debunscha, all in the rainforests of southwest Cameroon. Morphological structures show that both taxa are only remotely related, and that, while Nicsmirnovius is clearly an alonine, Bryospilus might well be a chydorine chydorid. Small, taxonomically non-significant differences occurred among specimens of Bryospilus recorded in three different forest areas.     

Occurrence of Cladocera (Crustacea) in subterranean waters in Yugoslavia

Contrary to some localities in France and Spain, Cladocera occur in hypogean waters in Yugoslavia very sporadically. Beside the stygobitic species, Alona hercegovinae from caves and Alona smirnovi from interstitial waters, particularly some other Chydoridae seem to be suited for hypogean life. Chydorus sphaericus, reputed as one of the most euryoecious cladocerans, occurs also the deepest in interstitial waters as well as in caves. Other species, found in hypogean waters are Simocephalus vetulus, Ilyocryptus sordidus, Eurycercus lamellatus, Chydorus ovalis, Leydigia leydigi, Acroperus harpae and Biapertura affnis.     

On species of the genus Lophocharis Ehrenberg, 1838 (Rotifera: Monogononta) from Uzbekistan

Three species of Lophocharis (Rotifera: Monogononta), collected from lakes and ponds of Uzbekistan, are described. Two are new to science, and one is recorded for the first time from Uzbekistan. Some data on the variability of these species are given.     

Demography of a population of Moina micrura kurz (Crustacea: Cladocera) in a temporary pond,peninsula of paraguaná, Venezuela

A population of M. micrura Kurz from a shallow, muddy and temporary pond, located in Peninsula of Paraguaná, western Venezuela, was studied from filling to drying phase. Population density, age structure, fecundity, and length of females, were determined. This population showed a low population density (< 50 ind/1), a low and density-dependent fecundity (mean eggs/adults = 1.3; mean clutch size = 2.1 eggs + embryos), and low juveniles to adults ratio (0.71). No significant correlation was detected between mean clutch size and mean body length of ovigerous females. Our results suggest effects of food limitations, and fish predation on demographic parameters of this population. Still, in unfavourable conditions, some demographics features associated to opportunistic species were evident.     

Mating behaviour in Moina brachiata (Jurine, 1820) (Crustacea,Anomopoda)

Information on mating behaviour in Anomopoda isavailable for very few species only, though matelocation and recognition certainly play an importantrole in maintaining reproductive isolation betweenspecies. Ephippial females and males of Moinabrachiata were observed in a drop of water under amicroscope for 10–20 minutes. Different combinationsof specimens were used, but copulation was onlyobserved when two males and two ephippial females wereplaced together. Males were very active, and oftentried to grasp a female, whereas females usually madeattempts to escape during the entire period of mating.Three phases were recognized: capture, positioning andcopulation. The male captured the female from thedorsal side, then moved to the ventral side and tooka position with its length axis being perpendicular tothat of the female, forming a sort of cross.Thereafter the pair started rotating around the lengthaxis of the female, while the male pushed thepostabdomen into the females brood pouch. Copulationlasted from 16 to 25 seconds. When different kinds offemales were used, males showed preference forephippial females with an empty ephippium and enlargedovaries. Our results indicate that not only visual andtactile cues may be important in identifying speciesidentity and receptivity of the female, but alsochemical signals.     

On the taxonomy of theDaphnia hyalina-galeata complex (Crustacea: Cladocera)

Populations of theDaphnia hyalina-galeata complex from Central, North and South Europe have been compared morphologically. The main purpose of this investigation is delimitation of the critical speciesDaphnia galeata, based on a thorough examination of the original materials from G. O. Sars' collection, and taking into account hitherto overlooked or insufficiently appreciated characters. According to their morphology and ecology,Daphnia hyalina, Daphnia galeata andDaphnia cucullata have to be treated taxonomically as separate species. In view of the short and high antennula mound and other morphological characteristics,Daphnia gracilis Hellich andDaphnia hyalina lacustris sensu Lilljeborg belong to the speciesDaphnia galeata. In the common range ofDaphnia galeata andDaphnia cacullata there occurs quite frequently an intermediary form, which according to genetic evidence is a hybrid of these two species. Although apparently this hybrid form is stabilized genetically to a large extent and is capable of identical reproduction, it should not be considered as a species in the usual sense.The present work intends to put the notoriously confused systematics of theDaphnia hyalina-galeata complex on a firm basis. It concludes with a key, which should enable also non-specialists to identify uniquely the three species and the hybrid form in question.     

Cytherella maremensis sp. n., a new ostracod from the Sea of Marmara (Turkey) (Crustacea: Ostracoda)

Cytherella maremensis sp. n., belonging to the family Cytherellidae, is described as new from a hydrothermal vent, located in the west of Marmara Island on the North Anatolian Fault crossing the Sea of Marmara. It was collected from a sediment core 55 m below sea level. Cytherella maremensis sp. n. is clearly separated from closely related species by its shape, length-height ratio and ornamentation.     

Significance of head and carapace pores inCeriodaphnia (Crustacea,Cladocera)

Twelve species ofCeriodaphnia were examined by light and scanning electron microscopy for the presence of head and carapace pores. Rostral pores, similar to those in the Scapholeberinae (Dumont & Pensaert, 1983) were found in all species, situated just anterior to or between insertions of the antennules. With two exceptions, the pattern of reticulations around the pores was distinctive for each species. Oval ‘head pores’ or fenestrae occur consistently on the anterior surface of the cervical notch of juvenile and adultC. dubia, cf.dubia (from Australia),lacustris, andreticulata. The patterns of reticulations around a fenestra are unique to each species. It appears thatC. cornuta (s.l.) in the Americas has a fenestra, whereas AustralianC. cornuta (s.s.) has none. Minute pores often occur bilaterally anterior and posterior to the cervical notch in heavily reticulated individuals of several species but are not constant enough to be taxonomically useful. Well-defined small pores are situated within narrow reticulations just medial to the ventral and posterior valve margins ofC. dubia, lacustris, andreticulata. These open into carapace glands of unknown, perhaps secretory, nature. Similar glands have been observed in related taxa. Such glands and marginal pores occur only occasionally or not at all in otherCeriodaphnia. Other small pores sometimes occur among reticulations of the head, fornix, and lateral and antero-ventral surfaces of the valves. They are found more often in juvenile or heavily reticulated individuals. As yet no consistent pattern to their occurrence among species has emerged. Head and carapace pores inCeriodaphnia may be most useful in identifying species rather than in determining species groups or evolutionary patterns within the genus.