The distribution of chydorid Cladocera in Canada

The distribution of chydorid Cladocera in Canada is given based on the examination of 584 samples collected from all the provinces and territories from 1978 through to 1984. Some species show regional distributions, while others are widely distributed. The preferences shown by some species to particular substrates are discussed. Further evidence is presented to show that some taxa previously claimed to be conspecific in Europe and North America may be different. In some instances the adult males tend to be more highly differentiated than the females, particularly in the structure of the postabdomen. The importance of taxonomic and distributional studies in understanding the biogeography of North American chydorids is discussed.     

The rotifers of Warri River, Nigeria

The rotifer assemblage of the dendritic tidal Warri River wasinvestigated at four sampling points from July 1981 to July1982. Forty-one species of Rotifera were identified. Five ofthese — Anuraeopsis racenesi Berzins Keratella cochlearismacracantha Lauterbom, Monostyla lunaris Pawlowsky,M. stenroosiMeissner and Trichocerca similis grandis Hauer — are beingrecorded for the first time in West Africa. The Warri Riverrotifers are 65% cosmopolitan and 20% pantropical although therewas no species limited to African waters only. The dominantrotifers in the Warri River were Keratella tropica and K. cochleariswhich were found in the predominantly freshwater sampling stationat Udu Bridge to Warri and Orugbo Creek where low brackish watersalinities and conductivities are observed from December orJanuary to April each year. The preponderance and longitudinaldistribution of these two well-known cyclomorphic rotifers providesan opportunity to study their salinity tolerance and the effectof salinity and conductivity on their cyclomorphosis by samplingalong the length of the river from Udu Bridge to Forcados wherethe Warri River joins the Atlantic Ocean.     

Distribution of endosulfan in water, sediment and fish from Warri river, Niger delta, Nigeria

This article presents the first attempt to quantify the levels and distribution pattern of endosulfan, an organochlorine pesticide in surface water, sediment and fish ( Chrysichthys furcatus and Tilapia zilli ). The samples were collected from three stations (Ovwian, Ekakpamre and Ovu) of Warri River in the western Niger Delta of Nigeria in 2006 during the dry and wet seasons (January–August). A total of 96 samples made up of 24 samples each for water, sediment and fish were analysed in this study. The pesticide levels were analysed using high performance liquid chromatography (HPLC model CECIL 1010) to elucidate its distribution in various environmental compartments. The ranges of concentrations of the pesticide in the matrices were: 0.01–9.23 μg/l (water), 0.06–11.98 μg/gdw (sediment), 0.01–15.06 μg/gdw ( Chrysichthys furcatus) and 0.01–1.80 μg/gdw ( Tilapia zilli ). From this result, decreasing order of occurrence of the pesticide is as follows: fish > sediment > water. The concentrations observed in fish ( Chrysichthys furcatus ) were higher than the levels observed in sediment and water suggesting bioaccumulation of the pesticide by the fish. Spatial variations occurred with downstream stations having statistically higher concentrations in all matrices at P  < 0.05. Seasonal variations occurred with higher concentrations in dry season for water and sediment only, while the fish species had higher concentrations in the wet season. The observed values of endosulfan were above the ecological bench marks (0.02 μg/l) recommended by Nigeria Environmental Protection Agency and European Union. They were also relatively higher than those in previous studies on the Nigerian environment, an observation that calls for regular monitoring of the Niger Delta water bodies.     

Some remarks on the latitudinal distribution of Cladocera on the Indian subcontinent

One hundred and thirty species of Cladocera have been recorded from the Indian subcontinent which extends from 6°N to 37°N latitude and covers an area of 4.5 million km². The equatorial region has few Daphnia species, all belonging to the sub-genus Ctenodaphnia while the more northern parts have more species of Daphni including Daphnia s. str. The limnetic Cladocera lacks the carnivorous Polyphemidae and Leptodoridae at lower latitudes (equatorial). The common limnetic species of the equatorial region are eurytopic and extend throughout the subcontinent.     

Salinity tolerance and morphology of the osmoregulation organs in Cladocera with special reference to Cladocera from the Aral sea

The hyperosmotic regulation of adult Cladocera is determined mainly by the amount of salts consumed with the food and by reabsorption of salts in cells of the nuchal (neck) organ. The hypoosmotic regulation both in adults and embryos is determined mainly by excretion of salts in special epipodite cells or in cells of the nuchal (neck) organ. The salinity of the Aral sea for the last 30 years increased from 8–10 to 26–28, which led to changes in the Cladocera fauna. At present only 4 species of Cladocera inhabit the Aral sea instead of 14 species that were previously found. These changes are in agreement with osmoregulation capacities of Cladocera. Note added in proof. Since this paper was accepted for publication, all Cladocera have disappeared from the Aral Sea. This happened when salinity reached 30–32. This disappearance was predicted by and agrees with earlier laboratory experiments with Aral Sea Cladocera (Aladin, 1982b).     

Halicyclops korodiensis Onabamiro (Crustacea,Copepoda) in the estuary of the Warri River,Nigeria, West Africa

Halicyclops korodiensis Onabamiro was recorded in plankton samples of the brackish waters of the Warri River, Nigeria, West Africa. It is redescribed and figured.     

Cladocera from pokhara valley,nepal with notes on distribution

A study made on collections of zooplankton from lakes and ponds in Pokhara Valley, Nepal yielded 23 species of Cladocera of which 1 i species are recorded for the first time in Nepal. This brings the recorded Nepalese Cladocera to 39 species. All the species recorded in the present study are illustrated and described briefly. A compilation of previous and present records is given with a short discussion of the species composition.     

Body fat distribution of children and adolescents in Abeokuta,Southwest Nigeria

Excessive central fat in children and adolescents is a risk factor for cardiovascular and metabolic disorders. This study aimed to compare the body fat distribution patterns of children and adolescents in Abeokuta, Nigeria with international reference standards. Five hundred seventy children aged 5 to 19 years were selected from seven schools using multistage random sampling. Weight, height, triceps and subscapular skinfold thickness (TSF, SSF), and circumference at the waist and hips (WC, HC) were measured. Body mass index (BMI), subscapular:triceps skinfold ratio (STR), waist:hip circumference ratio (WHR), and waist: height ratio (WHtR) were derived. Females had higher mean BMI, TSF, SSF, WC, HC, WHR, and WHtR, while males had significantly higher STR. The mean BMI, WC, TSF, and SSF values were lower for our subjects than for African‐American subjects at all ages. On the other hand, in both sexes, STR was higher among Nigerian than African‐American subjects up to 12 years old. Thereafter the values were similar. The mean WC was similar to those reported for African‐American males up to 8 years, and females up to 7 years of age; thereafter, African‐American had higher values. The prevalence of central obesity using WC and WHtR measures was 4.4% and 5.8%, respectively. There is a need to validate each index against serum lipid profiles and other cardiovascular and metabolic risk factors. Am J Phys Anthropol 150:647–654, 2013. © 2013 Wiley Periodicals, Inc.     

Altitudinal distribution of tropical planktonic Cladocera

The altitudinal distributions of planktonic Cladocera in Africa in three latitudinal bands: 0–10 °, 10–20 ° and 28–31 ° are described. Some species have altitudinal ranges of 2000 m within a latitudinal band of 10 °. It is possible to distinguish tropical species which do not extend up to high altitudes, particularly at higher latitudes. At the lowest latitudes, some species are found only at high altitudes, but occur at progressively lower altitudes with increasing latitude: Daphnia pulex and D. obtusa are good examples. A study in South America, with a smaller database, gives similar results.     

Contributions to the knowledge of the Cladocera of north-east Thailand

Examination of 200 samples from 93 freshwater habitats in north-eastThailand revealed 60 taxa of Cladocera, of which 31 are new to the Thaifauna. Six species (Disparalona caudata Smirnov; Leydigialaevis Gurney; Leydigiopsis sp.; Macrothrix flabelligeraSmirnov; Macrothrix cf. paulensis Sars; and Pseudosidaramosa Daday) are new to Asia. The majority of the Cladocera recorded arecircumtropical species. Comments and figures are presented on several ofthe new records for Asia and Thailand. This revised version was published online in July 2006 with corrections to the Cover Date.     

Fish species diversity as indicator of pollution in Ikpoba River, Benin City, Nigeria

The composition and distribution of fish in the Ikpoba reservoir were investigated. A total of fifty-seven species of fish belonging to thirty-nine genera and twenty-three families were recorded. Of these, 46 species were recorded at the upstream station, 35 at the reservoir, 24 at the slope and 32 at the downstream station. The percentage compositions were 81%, 61%, 42% and 56% respectively. There were 21 ubiquitous species while the distribution of the other species showed variability indicating effects of habitat condition. Species diversity indices showed that the upstream section was richer, more diverse with species more evenly distributed than the other stations. Heavy metal analysis of the dominant fish species showed higher mean levels than the background levels. Metal contamination factor and bioaccumulation quotient were variable in the fishes and in the stations but followed a ranked order of 3 > 2 > 4 > 1 by station. Comparison of stations using ANOVA revealed a significant difference (P < 0.05) between the upstream and the slope stations.     

Concentrations and Distribution of Trace Metals in Water and Streambed Sediments of Orogodo River,Southern Nigeria

The distribution of Cd, Pb, Ni, Cr, Cu, Mn, Fe, and Zn in sediment and surface water, and some physico-chemical characteristics of Orogodo river sediments, were evaluated. The sediment pH ranged from 5.1–7.3; conductivity values ranged from 34.5 to 389.0 μScm^?1. Total nitrogen values ranged from 0.06–0.10%, NH₃-N values ranged from 0.25–0.44 mgkg^?1, percent total organic carbon ranged from 0.21–1.68%, and total phosphorus values ranged from 0.004–0.02% for dry and wet seasons. The sand fraction consists of 87–95%, silt fractions ranged from 0–2%, and clay fraction between 4–13%. The mean concentrations of metals (dry weight basis) in the streambed sediments ranged from 1.92–17.37 mgkg^?1 for Cu, 0.98–4.78 mgkg^?1 for Ni, 0.01–32.98 mgkg^?1 for Mn, 353.22–2045.64 mgkg^?1 for Fe, 69.96–100.16 mgkg^?1 for Zn, 0.21–1.32 mgkg^?1 for Cr, and Cd was less than 0.001 mgkg^?1 for wet and dry seasons. The mean concentrations of metals in the surface water ranged between 0.01–0.05–0.05 mg/L for Cu, nd-0.11 mg/L for Ni, 0.001–0.31 mg/L for Pb, 0.001–1.82 mg/L Mn, 0.01–3.52 mg/L for Fe, 0.16–0.61 mg/L for Zn, nd-0.007 mg/L for Cr, and <0.001 mg/L for Cd. Based on principal component analysis, two main sources of metals in the Orogodo River can be identified: (i) Cr, Cu, Pb, and Fe are mainly derived from industrial sources; (ii) Mn, Zn, and Ni associated with traffic activities. No element examined had a contamination/pollution index value greater than unity (pollution ranges). This implies that the multiple pollution indices obtained from the analysis showed that Orogodo River sediments were not polluted with heavy metals.     

Morphology and the classification of the so-called Cladocera

The validity as a monophyletic taxon of the group of branchiopod crustaceans long regarded as constituting the Cladocera is questioned. This seems in fact to be a heterogeneous assemblage whose members probably merit assignment to four separate orders. The Onychopoda and Haplopoda (the so-called Gymnomera) clearly stand apart from the Ctenopoda and Anomopoda (the so-called Calyptomera) and differ in important respects from each other. While sharing several characters, some doubtless indicative of distant ancestral similarities, others probably convergent, the Ctenopoda and Anomopoda differ in many respects, have clearly evolved along different lines, and are probably much less closely related than is generally assumed.     

Factors affecting the distribution and abundance of Cloeon and Caenis (Ephemeroptera) larvae in a tropical impounded river, Nigeria

Impoundment of rivers affects the mayfly (Ephemeroptera) fauna inhabiting such water bodies, especially with respect to their distribution and abundance. A two‐year study of the mayfly fauna and some of the physicochemical parameters of the Opa stream–reservoir revealed that there are two mayfly genera inhabiting it, Cloeon and Caenis. The number of Cloeon larvae collected was 10,930 while the number of Caenis larvae was 450. It was observed that although both genera occurred at all the sampling stations, their numbers were reduced in the stream below the dam due to increased water current velocity. There were significant differences in the abundance of Cloeon among the stations, but none for Caenis. Submerged aquatic plants and water current velocity were found to be the major factors responsible for the significant differences. There were significant correlations between the number of Cloeon larvae and pH as well as between dissolved oxygen concentration and Caenis. These findings are discussed with reference to inter‐specific differences in patterns of response to environmental parameters. A species‐specific approach is suggested for studies on the strategies that enable mayfly species maintain their populations in stressed and unstable aquatic ecosystems.     

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.     

Cladocera of coastal rivers of western Nigeria

Recent studies indicate that there are at least 100 species of Cladocera in the families Bosminidae, Chydoridae, Daphnidae, Macrothricidae, Moinidae and Sididae in the inland waters of Nigeria. Over 50% of these have been found in net plankton samples from the coastal rivers in addition to Evadne tergestina Claus (Family: Podonidae), and Daphnia barbata Weltner, hitherto unreported in the equatorial lowlands of Africa. In effect, the Cladocera of the coastal rivers and creeks consist of the marine/brackish assemblage made up of Penilia avirostris Dana and Evadne tergestina and the freshwater assemblage made up of all other Cladocera found. Unlike in the more inland water bodies, the freshwater assemblage of the coastal rivers is dominated by the Bosminids Bosmina longirostris (O. F. Muller) and Bosminopsis deitersi Richard. The distribution, seasonality and successional patterns of Cladocera in the coastal water bodies of Western Nigeria is presented.     

A checklist of the Cladocera of Israel and Eastern Sinai

Sixty species of Cladocera are recorded from Israel and Eastern Sinai after the examination of several collections, and include 18 new records for the area as well as 9 species known only from the literature. Chydoridae dominate the fauna, with 27 species recorded, followed by Daphniidae with 21 species.     

On the resurrection of the cladoceran species Chydorus reticulatus Daday, 1898 (Chydoridae,Cladocera) and its relationship to Chydorus ventricosus Daday, 1898

The chydorid species Chydorus reticulatus Daday, 1898 and Chydorus ventricosus Daday, 1898 are redescribed and literature records reevaluated on the basis of new material from India.Contribution 9 Department of Biology, Indiana University, Bloomington. This study was supported in part by NSF Grant DEB76-20237 to D. G. Frey.