Diversity and distribution of copepods (Class: Maxillopoda, Subclass: Copepoda) in groundwater habitats across South-East Asia

Abstract

Copepods have successfully penetrated the groundwater realm through a series of morphological diversifications and adaptations. Research on this taxon has increased over the past decade because of its potential in revealing the status of groundwater environmental health and biodiversity. Despite efforts in documenting this group in other regions, groundwater copepods in South-East Asia remain barely studied. To date, only 47 species belonging to 22 genera from Harpacticoida, Cyclopoida and Calanoida have been documented from groundwater and groundwater-dependent habitats across the region. The steep species accumulation curve from 1980 up to the present indicates a high possibility of discovering more new species. Spatial distribution shows high local endemicity than regional scales, where some species considered to be rare and endemic were actually common in local habitats. Overall, the low number of records in the region is because of the lack of experts and limited accessibility to groundwater and dependent ecosystems, like aquifers and groundwater wells. A more intensive effort in documenting the diversity and distribution of groundwater copepods and building collaborations between experts in the region is highly needed. This information is important in drafting future conservation and management policies for the groundwater resources in the region.

Two New Species of Parastenocaris (Copepoda, Harpacticoida) from a Hyporheic Zone and Overview of the Present Knowledge on Stygobiotic Copepoda in Vietnam

“…Enp-2 with two elements apically, one long geniculate seta, and one spine. Exp-1 about 2.5 times as long as wide, with one strong outer spine at 3 4 of its length. Exp-2 without outer spine or seta, about 1.2 times as long as wide.…”

“…Exp-1 similar to Exp-1 of P2. Exp-2 with one short outer spinule at 3 4 length of margin; one short inner spinule, one unilaterally pinnate outer seta apically and one spiniform unilaterally pinnate seta sub-apically. P4 (Figure 6B) coxa trapezoidal.…”

“…In Vietnam, the known number of stygobiotic Copepoda (i.e., strict groundwaterdwelling species) is still quite limited, although the number of species increased significantly-from five species before 2010 to twelve at present (Table 1). This is still rather low compared to 25 stygobiotic copepods species from Thailand, which is among the best-investigated country in the region [2,3] This number indicates the high potential for stygofauna there, not only among Copepoda Until now, over 290 species and subspecies belonging to the family Parastenocarididae have been reported worldwide [4], of which only three have been recorded from freshwater habitats in Southeast Asia. One species has been reported from the Philippines and one from Malaysia [2].…”