Proserpinicaris wangpi, Karanovic & Cho & Lee, 2012

Karanovic, Tomislav, Cho, Joo-Lae & Lee, Wonchoel, 2012, Redefinition of the parastenocaridid genus Proserpinicaris (Copepoda: Harpacticoida), with description of three new species from Korea, Journal of Natural History 46 (25 - 26), pp. 1573-1613 : 1591-1597

Proserpinicaris wangpi sp. nov.

( Figures 7–9 )

Synonyms

Parastenocaris nipponensis Chappuis : Miura, 1969: 253, figs 47–51.

[partim.] Parastenocaris ondali sp. nov.: Lee and Chang, 2009: 170.

[non] Parastenocaris nipponensis Chappuis : Chappuis, 1955: 187, figs 23–29; Chappuis, 1958: 429, fig. 12; Miura, 1964: 140, figs 45–54.

Type locality

South Korea, Gyungsangbuk-do region , Uljin city, Geunnam town, Wangpi stream, interstitial water from several beaches on banks, 36 ◦ 57 ′ 41.4 ′′ N 129 ◦ 22 ′ 46.4 ′′ E .

Specimens examined

Types only: holotype male, allotype female, three paratypes (one male and three females) together on one scanning electron microscopy stub (collection number NIBRIV0000232619); four paratypes (one males and three females) dissected on one slide each (collection numbers NIBRIV0000232620 to 0000232623); additional three paratype females together in alcohol (NIBRIV0000232624); 12 paratypes from separate sample (two males, six females and four copepodids) together in alcohol (NIBRIV0000232625); all collected from type locality, 18 May 2010, leg. J.-L. Cho, all deposited in the National Institute of Biological Resources , South Korea .

Etymology

The species name refers to its type locality, Wangpi stream, and should be treated as a noun in apposition to the generic name.

Description

Male (based on holotype and several paratypes). Total body length from 355 to 373 µm (360 µm in holotype). Colour, body segmentation, arthrodial membranes, and sensilla pattern as in P. young sp. nov. (see above). Habitus ( Figure 7A ) cylindrical and slender, without any demarcation between prosome and urosome; prosome / urosome ratio 0.7; greatest width hard to establish in dorsal view; free prosomites in lateral view narrower than cephalothorax and even slightly narrower than urosome. Body length / width ratio about 8.8; cephalothorax about as wide as genital somite. Free pedigerous somites without any expansions laterally or dorsally. Hyaline fringes of all somites smooth, very narrow and hard to distinguish from arthrodial membranes, except in preanal somite dorsally and partly laterally. Integument weakly sclerotized, very smooth, without any spinules or cuticular pits (except several spinules on caudal rami), ornamentated with 45 pairs of sensilla and four pairs of pores (three on anal somite, and one on caudal rami), dorsally with round cuticular window on cephalothorax and oval cuticular windows on genital and three postgenital somites, all in same position and of similar size to those in P. young . Pleural areas of cephalothorax ( Figure 7D ) and free pedigerous somites ( Figure 7A ) not well developed, cephalic appendages and coxae of swimming legs clearly exposed in lateral view; rostrum and cuticular sutures of free pedigerous posomites as in P. young .

Cephalothorax ( Figure 7A,D ) about 1.5 times as long as wide in dorsal view; representing 17 % of total body length.

Urosomites ( Figures 7A , 8A,B , 9A ) proportionately shorter and wider than in P. young , but without any other difference. Anal somite also about 1.2 times as long as preanal somite.

Spermatophore ( Figure 9A ) proportionately smaller and slenderer than in P. young .

Caudal rami ( Figures 7B , 9A ) much shorter than in P. young (arrowed in Figure 9A ), about 4.3 times as long as greatest width (ventral view) and about 1.2 times as long as anal somite, cylindrical, parallel, with space between them about 1.5 times one ramus’ width; armed with seven armature elements (three lateral, one dorsal and three apical). Ornamentation consists of large lateral cuticular pore near posterior margin, and posterior ventral row of three large spinules. Dorsal seta slender and smooth, inserted closer to inner margin of ramus at about five-sixths of its length, 1.3 times as long as caudal ramus, triarticulate. Lateral setae slender and smooth, inserted very close to each other at two-fifths of ramus length, minute one between two larger ones and slightly posterior to them. Anterior lateral seta inserted more dorsally, longest, 0.7 times as long as ramus, 1.4 times as long as other anterior seta, and about seven times as long as minute seta. Inner apical seta smooth, inserted close to ventral margin, about 0.6 times as long as ramus. Middle apical seta strongest, without breaking plane, unipinnate, about 1.5 times as long as ramus, pointing distally, with slightly curled tip. Outer apical seta also without breaking plane and unipinnate, relatively strong basally but much shorter, about 0.7 times as long as ramus, inserted close to dorsal surface and pointing laterally.

Antennula ( Figure 7C ) relatively large, eight-segmented, prehensile and digeniculate, with distal part much more strongly clasped (probably random post-mortem effect) and fifth segment more robust than in P. young , but armature and ornamentation without any difference, except aesthetasc on fifth segment wider and slightly longer.

Antenna, labrum ( Figure 7D ), mandibula ( Figure 7D ), maxillula ( Figure 7D ), maxilla ( Figure 7D ), maxilliped ( Figure 7D ), and first swimming leg as in P. young .

Paragnaths ( Figure 7D ) with eight large spinules in transverse row on posterior surface of central lobe.

Second swimming leg ( Figure 9C ) as in P. young , except endopod only about four times as long as wide (arrowed in Figure 9C ) and reaching three-fifths of first exopodal segment; apical seta 0.7 times as long as segment and pointing distally.

Third swimming leg ( Figures 7E , 9B ) with narrower basis and proximal exopodal segment (arrowed in Figure 9B ) than in P. young , and with shorter outer spine on proximal exopodal segment. Proximal exopodal segment 2.7 times as long as wide, with small tubular pore on posterior surface near inner margin (latter not observed in P. young ). Distal outer corner of proximal exopodal segment smooth (spinule missing). Leaf-like seta on apophysis more curved than in P. young .

Fourth swimming leg ( Figure 7F ) as in P. young , except apical seta on third exopodal segment somewhat shorter (about 2.2 times as long as third exopodal segment and 0.6 times as long as entire exopod); endopod and large basal spiniform process exactly as those in P. young .

Fifth leg ( Figure 8A,B ) represented by simple triangular cuticular plate, inner distal corner produced into distally serrate spiniform process (shorter than in P. young ), ornamented with four large spinules on inner margin, one arched proximal row of 14 minute spinules on posterior surface, and large cuticular pore on anterior surface; armature as in P. young .

Sixth legs ( Figure 8A ) smooth, unarmed and unornamented, forming simple operculum covering gonopore, slightly smaller than in P. young .

Female (based on allotype and several paratypes). Body length from 330 to 355 µm (335 µm in allotype). Habitus ( Figure 8C ), ornamentation of prosomites, colour and nauplius eye similar to male; genital and first abdominal somite fused into double somite and habitus less slender; free prosomites significantly narrower than urosomites in lateral view.

Genital double somite ( Figures 8C , 9D ) about as wide as long (dorsal view), without any trace of subdivision, with oval dorsal cuticular window in anterior half, much larger than that in male (originating from fused windows of two ancestral somites). Genital complex occupying anterior ventral half of genital double somite; genital apertures covered by vestigial sixth legs; median copulatory pores also covered by fused sixth legs; seminal receptacles small, trapezoidal in lateral view, hard to distinguish from internal tissue and gut content; copulatory duct very short and weakly sclerotized. All posterior sensilla homologous to those on male third urosomite, whereas two sensilla from male second urosomite missing (nos. 32 and 34).

Third ( Figure 8C ), fourth (preanal) ( Figure 8C ), and fifth (anal) ( Figure 8D ) urosomites similar to male.

Caudal rami ( Figures 8D , 9E ) slightly shorter in proportion to anal somite, from 3.6 to 3.9 times as long as wide, but also cylindrical and parallel, with armature and ornamentation as in male.

Antennula ( Figures 8C , 9F ) segmentation, ornamentation and armature as in P. young , except both aaesthetascs much more robust (arrowed in Figure 9F ).

Antenna, labrum, paragnaths, mandibula, maxillula, maxilla, maxilliped, first swimming leg, second swimming leg, exopod of fourth swimming leg similar to male.

Third swimming leg ( Figures 8C , 9H ) as in P. young , but with shorter apical element on second exopodal segment (arrowed in Figure 9H ).

Fourth swimming leg ( Figures 8C , 9J ) without spiniform process on basis. Endopod one-segmented, slightly curved, ornamented with apical row of two spinules at base of apical spine and three spinules on inner margin; apical spine not distinct at base, finely serrated (or bipinnate) distally, and about as long as endopod (i.e. proportionately longer than in P. young ; arrowed in Figure 9J ).

Fifth ( Figure 8C ) and sixth legs as in P. young .

Distribution

In addition to the type locality, Wangpi stream near Uljin city in South Korea ( Figure 12 ), this species probably lives in a well near Seongryu-gul cave at Uljin (less than 15 km away). Miura (1969) reported the latter population as Parastenocaris niponnensis Chappuis, 1955 , and Lee and Chang (2009) synonymized Miura’s record with their new species P. ondali Lee and Chang, 2009 , presuming a wide distribution of P. ondali in Korea. In the light of the presently discovered short range endemism in this group, both were probably wrong. Most morphological characters reported by Miura (1969) agree with Proserpinicaris wangpi sp. nov., and the proximity of the two locations suggests that these two populations are most probably conspecific. Hence, we think Miura’s record is likely to be synonymous with P. wangpi . Of course, the Japanese population of P. niponnensis is a distinct species.

Ecology

Specimens were obtained from several interstitial samples as well as from a well near a cave, which probably means that this species explores a wide range of subterranean habitats.

Figures

Figure 7. Proserpinicaris wangpi sp. nov., scanning electron micrographs, holotype male. (A) Habitus, ventral view; (B) anal somite and caudal rami, ventral view; (C) antennula ventromedial view; (D) mouth appendages, ventral view; (E) distal tips of third swimming legs and exopod of left fourth leg, ventral view; (F) coxa, intercoxal sclerite, basis, and endopod of fourth swimming leg, anterior view. Scale bars 30 µm for (A), 10 µm for (B, C), 3 µm for (D), and 2 µm for (E, F).

Figure 8. Proserpinicaris wangpi sp. nov., scanning electron micrographs, (A) holotype male; (B) paratype male; (C and D) allotype female. (A) Fifth pedigerous and genital somites, ventral view; (B) fifth legs, lateral view; (C) habitus, lateral view; (D) anal somite and caudal rami, lateral view. Scale bars 20 µm for (C), 10 µm for (A, D), 3 µm for (B).

Figure 9. Proserpinicaris wangpi sp. nov., line drawings, (A–C) paratype male; (D–J) paratype female. (A) Urosome, lateral view; (B) third swimming leg, posterior view; (C) endopod of second swimming leg, anterior view; (D) ventral part of genital double-somite, lateral view; (E) right caudal ramus, lateral view; (F) last four antennal segments with incomplete armature, ventral view; (G) endopod of second swimming leg, anterior view; (H) third swimming leg, anterior view; (I) endopod of third swimming leg, anterior view; (J) endopod of fourth swimming leg, anterior view. Scale bars 50 µm for all. Arrows indicate features different from previous species.

Figure 12. Distribution of the Proserpinicaris Jakobi, 1972 species in Korea: 1, P. imjin sp. nov.; 2, P. ondali (Lee and Chang, 2009); 3, P. wangpi sp. nov.; 4, P. young sp. nov.; 5, P. sp. See text for more explanation.