Lecane segersi n.sp. (Rotifera, Lecanidae) from Thailand

Lecane segersi n.sp. collected from a swamp in Udornthani province, northeastern part of Thailand, is described and figured. It is closely related to the common, warm-stenotherm Lecane papuana (Murray), but distinguished by the presence of inwardly directed antero-lateral spines.     

Toward a phylogeny and biogeography of Diaphanosoma (Crustacea: Cladocera)

Aquatic Ecology - Diaphanosoma s.l., with 40+? described species, is the largest genus of the Sididae and the Ctenopoda, similar in many ways to the anomopod genus Daphnia. Here, we offer a c...     

Comments on the morphology of Nicsmirnovius eximius (Kiser, 1948) (Aloninae,Anomopoda, Cladocera) in Thailand,with description of its male

The density, diet and habitat use of brown trout (Salmo trutta) and Siberian sculpin (Cottus poecilopus) were studied in the subalpine River Atna in southeastern Norway in the autumn during a six year period (1986–1991). There was an inverse relationship between the density of brown trout and Siberian sculpin. Diet overlap, as indicated by the Schoener index, was high between the two species, ranging between 0.48 and 0.86. Chironomid larvae and other aquatic insects were the most common food items for both species. Brown trout also consumed substantive amounts of surface insects. Siberian sculpin typically occupied sites with finer substrates and greater water depths than brown trout, even though there was considerable overlap in habitat use between the two species. Because the two species shared similar habitats, we suggest that the potential for species interactions exists, particularly at sites where density of sculpin is high.     

Mongolodiaptomus dumonti n. sp., a new freshwater copepod (Calanoida,Diaptomidae) from Thailand

Mongolodiaptomus dumonti n. sp. from several localities in northeast Thailand is described and figured. The new species shares some features with Mongolodiaptomus gladiolus (Shen & Lee), M. calcarus (Shen & Tai) and M. rarus (Reddy, Sanoamuang & Dumont), thus the gladiolus-group is created. However, it stands out in the female, by the extraordinary large postero-laterally spine at left proximal margin of genital somite. In the male, the right caudal ramus has a large tooth and a bilobed knob on ventral side; basis of the right P5 has a distinct, spur-like process on mid-distal surface; the second exopodite-segment of the right P5 has characteristically irregular outer margin, enlarged at proximal 1/3, but narrowed at distal 2/3 and bearing three lateral spines of unequal sizes; the inner margin of basis of the left P5 is fringed with a narrow hyaline lamella and dilated distally in lateral angle.     

A simplified method for preparing rotifer trophi for scanning electron microscopy

A simple, quick technique for the preparation of rotifer trophi for scanning electron microscopy is described. The method permits visual monitoring of the extraction process and does not require critical point drying of the specimens. Micrographs showing fine, structural detail of the hard parts of the mastax of representatives of the following genera are presented:Asplanchna, Conochilus, Filinia, Hexarthra, Keratella, Proalides, Synchaeta, andTrichocerca.