Chydoridae

Sinev, Artem Y. & Yusoff, Fatimah M., 2018, New data on Cladocera (Crustacea: Branchiopoda) of Sabah State, Borneo Island, Malaysia, Zootaxa 4438 (2), pp. 362-372 : 364-368

Family Chydoridae , subfamily Aloninae

Anthalona harti harti Van Damme, Sinev & Dumont, 2011 . A common Paleotropical species, already reported for Sabah ( Sinev & Yusoff, 2015). Numerous ephippial females and a single male were found in locality 5. Gamogenetic specimens of A. harti harti from South-East Asia were never described ( Van Damme et al., 2011). The only full description of male and ephippial female was provided by Alonso (1996) for Spanish populations (as Alona verrucosa Sars, 1901). The outer morphology of male and its postabdomen were briefly described by Sinev (2002) for the population from Caucasian coast of Black Sea (as Alona verrucosa), so a full description of these stages is provided.

Ephippial female. Body ( Fig. 1A ) of similar shape as in parthenogenetic female. Ephippium of freshly preserved specimens was intensive red-brown in color, with weakly defined egg locule, and weakly tuberculated.

Male. Body ( Fig. 1B ) low oval, height-length ratio about 0.6. Ocellus and eye are of the same size as in female, eye two times larger than the ocellus. Labrum ( Fig. 1C ) same as in female, with a blunt denticle bearing a spinule on anterior margin. Postabdomen ( Fig. 1D ) narrower than in female, evenly narrowing distally, not curved; ventral margin straight, with clear step in region of gonopores; gonopores located at 1/5 length of ventral margin from the end of postabdomen; distal margin almost straight; distal angle broadly rounded, slightly prominent; postanal and anal margin almost straight; distal part of postabdomen two times longer than preanal part; postanal angle not defined; preanal angle prominent, protruding; clusters of short setulae in place of marginal denticles; lateral fascicles of setulae similar to those of female; postabdominal claw short, about 2/3 length of postanal margin, weakly curved, with long thin basal spine about 1/4 length of claw itself.

Antennule ( Fig. 1E ) moderately long; length about 2.5 widths; male seta short, arising at 2/3 distance from the base and reaching the end of antennule; twelve terminal aesthetascs, longest of them about 2/3 length of antennule; all aesthetascs projecting beyond anterior margin of the head shield. Thoracic limb I ( Fig. 1F ) with short U-shaped copulatory hook 2.5 times shorter than limb itself ( Fig. 1G ); copulatory brush present, copulatory brush seta short; ventral face of limb below them with about 15 long setulae, followed by ten shorter setules; inner distal lobe ( Fig. 1H ) setae 2 and 3 subequal in length, much thinner than in female; male seta thick, almost straight, slightly shorter than seta 3.

TABLE]. Sampling sites in where clađocerans were founđ in Sabah, Malaysia

Abbreviation: Au, Australian; AuAs, Australasian; Or, Oriental (Indo-Malaysian); PaleoTr, Paleotropical; PanTr, Pantropical; PaleAr, Palearctic; SC?, probable species-complex; WD, widely distributed or cosmopolitan; B, benthic species; MA, macrophyte-associated species; PL, planktonic species; SA, surface-associated species.

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35. Chydorus parvus Daday, 1898. PaleoTr МА 36. Dadaya macrops (Daday, 1898). PanTr (SC?) SА 37. Dunhevedia crassa King, 1853. WD (SC?) МА 38. Dunhevedia serrata Daday, 1898. PaleoTr МА 39. Ephemeroporus barroisi (Richard, 1894). PaleoTr МА

*New records for Sabah.

** New records for Malaysia.

Morphology of studied specimens did not differ in any significant details from that of Iberian populations (Alonso 1996). This confirms identity of Mediterranean and South-East Asian population of the species.

Anthalona spinifera Tiang-nga, Sinev & Sanoamuang, 2016. Single specimen was found in locality 7 (oxbow lake in the valley of Padas river). Rare endemic of South-East Asia, so far known from North-East Thailand only ( Tiang-nga et al. 2016). The species is associated with macrophytes. Studied specimen had somewhat higher body ( Fig. 1I ) than in the Thailand population, but had the same distinctive morphology of labrum ( Fig. 1J ), postabdomen ( Fig. 1K ) and inner distal lobe of limb I ( Fig. 1L ). First record for Malaysia.

Kurzia brevilabris Rajapaksa & Fernando, 1986. Several specimens were found in locality 9 (pond in peat swamp area). Littoral species, associated with vegetation. For detailed description, see Rajapaksa & Fernando (1986). Species of Oriental region ( Rajapaksa & Fernando 1986), recorded for Malaysia by Idris (1983) as K. longirostris (Daday, 1898) .

Leberis diaphanus (King, 1853). Rather abundant in oxbow lakes in the valley of Padas river (localities 3, 6– 8), also found in localities 24–25. Littoral species, associated with vegetation. For detailed description see Neretina & Sinev (2016); for description of male see Sinev & Sanoamuang (2011). Distributed in Australia and South-East Asia ( Neretina & Sinev, 2016). Single ephippial female was found in locality 25. Ephippial females of L. diaphanus was never reported before ( Neretina & Sinev 2016), so the description is provided. Body similar to that of parthenogenetic female ( Fig. 1M ), but with well-defined posterodorsal angle of valves. Ephippium without distinctive sculpture, yellowish, with weakly developed egg locules.

Figures

FIGURE 1. Cladocera from Sabah, Мalaysia. А–G, Anthalona harti harti Van Damme, Sinev & Dumont, 2011 from locality 2. А, ephippial female. B–G. adult male. B, lateral view. C, labrum. D, postabdomen. E, antennule. F, thoracic limb I (cbs – copulatory brush seta). G, copulatory hook of thoracic limb I. H, inner distal lobe (IDL) of thoracic limb I (ms, male seta). I–L, Anthalona spinifera Tiang-nga, Sinev & Sanoamuang, 2017 from locality 7, parthenogenetic female. I, lateral view. J, labrum. K, postabdomen. L, inner (IDL) and outer (ODL) distal lobes of thoracic limb I (as, accessory seta). М, Leberis diaphanus (King, 1853) from locality 25, ephippial female.