A Review of the Genus Thermocyclops - Zoological Studies

Chaicharoen et al. – Review of Thermocyclops in Cambodia 781framing a project with the goal of revising thefreshwater cyclopoid and calanoid fauna ofCambodia, we organized 3 collecting trips in 2007and visited 7 provinces of the country. The presentreport is based on that material.MATERIALS AND METHODSIn total, 252 samples were analyzed from7 provinces (Banteay Meanchey, Battambong,Siem Reap, Kampong Thom, Pursat, Kratie,and Stung Treng) of Cambodia. Collection dataare given at the descriptions of the particularspecies, and the localities are also shown on amap (Fig. 1). Unless otherwise stated, specimenswere collected by the senior author. Specimenswere measured in glycerol, with bright-field anddifferential interference contrast optics. Drawingswere made using a camera lucida on an OlympusBX50 compound microscope (Tokyo, Japan).Telescoping segments of the prosome andurosome were measured separately, yet bodylength (BL) was measured as the distance betweenthe anteriormost point of the cephalothorax andposteriormost point of the caudal ramus. Thelength of pediger 4 was measured as the distancebetween its anteriormost and posteriormost points.Only females were identified and are describedhere, as the identification keys (e.g.Mirabdullayev et al. 2003) do not include charactersof the male, and information on male morphologyis very fragmentary.The following abbreviations were used: enp,endopodite; exp, exopodite; P1-P4, swimminglegs 1 to 4; S1, medialmost terminal caudal seta;S2, inner median terminal caudal seta; S3, outermedian terminal caudal seta; S4, lateralmostterminal caudal seta; S5, dorsal caudal seta;SMNK, Staatliches Museum für NaturkundeKarlsruhe (Karlsruhe, Germany).NTHAILANDLAOS PDRBantean MeancheySiem ReapStung TrenghMekong RiverLake SapKampong ThomKratieBattambongPursatVIETNAMFig. 1. Collecting localities of Thermocyclops species in Cambodia.