Diversity, Distribution, and Habitat Occurrence of the Diaptomid Copepods (Crustacea: Copepoda: Diaptomidae) in Freshwater Ecosystems of Thailand

The diversity, distribution, and checklist of diaptomid copepods from various freshwater ecosystems throughout Thailand are presented, based on data from our biodiversity projects during 1993–2019 and literature reviews. Thailand has one of the most diversified diaptomid fauna in the world, with 42 species identified from 2150 localities (4962 samples). Mongolodiaptomus has the highest species richness with ten species, followed by Tropodiaptomus with seven species. Among these, eight taxa (Arctodiaptomus sp., Mongolodiaptomus pectinidactylus, Neodiaptomus meggitti, Tropodiaptomus hebereri, T. lanaonus, T. oryzanus, T. ruttneri, and Paradiaptomus greeni) are new to the fauna of Thailand. The rare P. greeni, which predominantly occurs in Africa, is also a new record for Southeast Asia. The most frequently encountered species were Mongolodiaptomus botulifer, Phyllodiaptomus praedictus, M. calcarus, M. dumonti, M. malaindosinensis, Vietodiaptomus blachei, Phyllodiaptomus christineae, Eodiaptomus sanoamuangae, Neodiaptomus yangtsekiangensis, E. draconisignivomi, T. vicinus, and Heliodiaptomus elegans. Twelve species appear to be endemic to Thailand, and eight species occur only in the countries belonging to the lower Mekong River Basin (Thailand, Cambodia, Laos, and Vietnam). The uniqueness of the Thai diaptomids is a high degree of co-occurrence of four to seven species in the same localities. Comments on the taxonomic status of the species recorded are provided. In addition, the taxonomic validity of Mongolodiaptomus malaindosinensis is discussed.

First record of Arctodiaptomus wierzejskii (Richard, 1888) (Copepoda Calanoida Diaptomidae) from Malta

Diaptomid copepods belonging to the genus Arctodiaptomus Kiefer, 1932 were collected in two temporary water bodies in Malta. The morphological identification of the collected specimens proved that they belong to Arctodiaptomus wierzejskii (Richard, 1888) even if a morphological peculiarity pertaining to the morphology of the male right antennule of the Maltese populations was observed and here briefly discussed. This finding constitutes the first record of a calanoid copepod from the inland waters of the Maltese Islands.

Updated checklist and distribution of the diaptomid copepods (Copepoda, Calanoida, Diaptomidae) of China

We present an updated checklist of the Diaptomidae of China, based on a literature review and on original field data from all over China during 2012-2016. A total of 19 genera and 56 species have been recorded. Neutrodiaptomus has the highest species richness (10 species), followed by Arctodiaptomus (9 species). Only one species each of Eudiaptomus, Mixodiaptomus, Eodiaptomus, Dentodiaptomus, Dolodiaptomus, Allodiaptomus, Karstodiaptomus, Metadiaptomus and Paradiaptomus was found. The taxonomic status of 16 species was revised: one wrongly attributed genus, Argyrodiaptomus, was corrected to Sinodiaptomus. First records for China include Arctodiaptomus parvispineus and one new cave-dwelling genus, Karstodiaptomus, is added. One Latin name from Shen & Sung’s book (1979) is corrected. Remarks on nomenclature and taxonomic issues are supplemented with information on the geographical distribution of the various species within China.

The freshwater diaptomid copepod fauna (Crustacea: Copepoda: Diaptomidae) of the Western Ghats of Maharashtra with notes on distribution, species richness and ecology

<p>The diversity of many invertebrate taxa from Western Ghats of Maharashtra remains unknown due to lack of systematic studies. We studied freshwater calanoid copepods from this region, and found eleven species of diaptomid copepods in 180 samples collected from 80 sites in the study area. Most of these are new records for this region. The observed fauna includes Oriental, Gondwanan, Palaearctic and Indian endemic taxa. Locality data for all the observed species, along with notes on some ecological aspects of the sampled sites are provided. Non-parametric estimates of species richness for the region suggested an overall adequacy of sampling effort, and probable missing out of some species from habitats with longer hydroperiod. Hydroperiod, depth, electrical conductivity, altitude, mean annual temperature and latitude largely influenced the distribution of species in the study area. Co-occurrences of species were overall rare but more common in temporary habitats. Assemblages of diaptomid copepods restricted to certain sites were identified. The importance of temporary habitats is discussed in the light of their species richness, faunal composition and the increasing anthropogenic pressures they face.</p>

Chorion Structure of Diapause and Subitaneous Eggs of Four Diaptomid Copepods (Calanoida, Diaptomidae): SEM Observations

Chorion Structure of Diapause and Subitaneous Eggs of Four Diaptomid Copepods (Calanoida, Diaptomidae): SEM ObservationsScanning electron microscopic examination of diapause eggs of freshwater CalanoidaHemidiaptomus amblyodonMarenzeller,Eudiaptomus vulgaris(Schmeil),E. graciloides(Lilljeborg) and subitaneous one s ofE. gracilis(Sars) is described. The chorion surface ornamentation and number of coated layers are revealed. Diapause eggs have a thick (0.6-4.8 μ), at least two-layered chorion with patterned surface, whereas subitaneous eggs have a thin (0.13-0.25 μ), single-layered chorion with smooth surface. The mean number of eggs in egg sac, diameter of eggs and thickness of chorion were measured. The significance of the egg chorion thickness for diaptomid species inhabited temporary and/or permanent water-bodies is discussed.