Proserpinicaris young Karanovic & Cho & Lee 2012, sp. nov.
Creators: name: Karanovic, Tomislav
name: Cho, Joo-Lae
name: Lee, Wonchoel
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Hexanauplia
Harpacticoida
Parastenocarididae
Proserpinicaris
Proserpinicaris young

description: Proserpinicaris young sp. nov.   
(Figures 1–6)  
 Type locality   
 South Korea, Gyungsangbuk-do region, Sanggu city, Young river, interstitial water from sandy beaches on banks, 36 ◦ 31 ′ 42.8 ′′ N, 128 ◦ 14 ′ 02.7 ′′ E.   
 Specimens examined   
Types only: holotype male, allotype female, seven paratypes (three males and four females) together on one scanning electron microscopy stub (collection number NIBRIV0000232611); six paratypes (four males and two females) dissected on one slide each (collection numbers NIBRIV0000232612 to 0000232617); additional 36 paratypes (18 males, 11 females, and seven copepodids) together in alcohol (NIBRIV0000232618); 25 paratypes (10 males, 10 females, and five copepodids) sent for DNA barcoding; all collected from type locality, 24 April 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, the Young river, and should be treated as a noun in apposition to the generic name.  
 Description   
 Male (based on holotype and several paratypes). Total body length, measured from tip of rostrum to posterior margin of caudal rami (excluding caudal setae), from 375 to 406 µm (400 µm in holotype). Preserved specimen colourless. Nauplius eye absent. Body composed of prosome [consisting of cephalothorax and three free pedigerous somites (first pedigerous fused to cephalothorax)], and urosome (consisting of fifth pedigerous somite, genital somite, four abdominal somites, and caudal rami). Podoplean boundary between prosome and urosome inconspicuous. Habitus (Figures 1A, 3A) cylindrical and very slender, without any demarcation between prosome and urosome; prosome / urosome ratio about 0.9 in dorsal view; greatest width in dorsal view at fourth and fifth pedigerous somites, but hard to establish; free prosomal somites in lateral view narrower than cephalothorax or urosome. Body length / width ratio 8.1; cephalothorax about as wide as genital somite. Free pedigerous somites without any lateral or dorsal expansions, all connected by well developed arthrodial membranes. Hyaline fringe of all somites smooth, very narrow and hard to distinguish from arthrodial membranes, especially dorsally, except in preanal somite, with hyaline fringe well developed dorsally and partly laterally, but not ventrally (Figures 1A, 3A, 4A,B). Integument weakly sclerotized, smooth, ornamented only with sensilla and pores (no spinules or cuticular pits), with round dorsal double cuticular window on cephalothorax, and oval dorsal simple cuticular windows on genital and three postgenital somites. Pleural areas of cephalothorax and free pedigerous somites not well developed, cephalic appendages and coxae of swimming legs clearly exposed in lateral view.   
Rostrum (Figure 3C) small, membranous, not demarcated at base, ornamented with two large dorsal sensilla, linguiform, not reaching distal margin of first antennular segment, about as long as wide.  
Cephalothorax (Figures 1A,E, 3 A–C) about 1.8 times as long as wide in dorsal view; representing 21% of total body length. Surface of cephalic shield ornamented with 16 pairs of large sensilla (numbered from anterior to posterior and from dorsal to ventral side in Figure 3B,C); no small sensilla, cuticular pores, pits, or any other ornamentation; five pairs of sensilla surround double cuticular window, but its surface completely smooth; except for one pair of sensilla (no. 11) visible from dorsal view. Arthrodial membrane between cephalothorax and second pedigerous somite (first free) larger than between any other somites.  
Second pedigerous somite (Figures 1A, 3 A–C) as wide as posterior half of cephalothorax in dorsal view, with four pairs of large sensilla (three dorsal and one lateral; nos. 17–20), and with arched dorsal sutures in anterior half joining to make interesting crown-like pattern.  
Third pedigerous somite (Figures 1A, 3 A–C) slightly wider and longer than second, with five pairs of large sensilla (nos. 21–25), also with arched dorsal sutures making crown-like pattern, but less pronounced than in second pedigerous somite.  
Fourth pedigerous somite (Figures 1A, 3 A–C) widest prosomal somite in dorsal view, slightly longer than third, with only three pairs of large posterior sensilla (nos. 26–28), with deeper and longer arched sutures than in any other somite.  
First urosomite (Figures 1A,D, 4A,B) about as wide as fourth pedigerous somite but slightly shorter, also with three pairs of large posterior sensilla (nos. 29–31), with two small arched dorsal sutures in anterior half, and with nearly continuous horizontal suture in posterior half at level of sensilla insertion.  
Second urosomite (= genital somite) (Figures 1A,D, 4A,B) slightly narrower and shorter than first, with oval dorsal cuticular window in anterior half, also with three pairs of posterior sensilla (nos. 32–34), but two dorsal pairs (nos. 32 and 33) closer to each other than in first urosomite.  
Third urosomite (Figures 1A, 4A,B) about as long as second but slightly narrower, with shorter and wider dorsal cuticular window, and with five pairs of large posterior sensilla (nos. 35–39); two dorsal pairs (nos. 32 and 33) much closer to each other than in second urosomite.  
Fourth urosomite (Figures 1A, 4A,B) slightly narrower than third, but also with five pairs of large posterior sensilla (nos. 40–44), and with similar sized dorsal cuticular window.  
Fifth urosomite (= preanal somite) (Figures 1A, 4A,B) slightly narrower and longer than fourth, with largest dorsal cuticular window of all urosomites, and without any surface ornamentation.  
Sixth urosomite (= anal somite) (Figures 1A, 2A, 4A,B) about 1.2 times as long as and slightly narrower than preanal somite, ornamented with pair of large dorsal sensilla at base of anal operculum, pair of large lateral cuticular pores in anterior half, pair of ventral pores at base of caudal rami, and pair of minute ventro-lateral pores in posterior eighth of somite length (no spinules on ventral surface). Anal operculum well developed, unornamented on outer surface, with smooth and almost straight distal margin, not reaching posterior end of anal somite, representing 70% of somite’s width. Anal sinus widely opened, ornamented with two long diagonal rows of slender spinules on ventral side, and two parallel rows on dorsal side (inner side of anal operculum).  
Spermatophore (Figure 3D) about twice as long as wide, kidney-shaped, with narrow and curved neck. Note that spermatophore neck and its opening squeezed out and visible in upper right corner in Figure 1D.  
Caudal rami (Figures 1A, 2A, 4A,B) very long and slender, about six times as long as greatest width (ventral view) and about 1.4 times as long as anal somite, cylindrical, parallel or slightly divergent, with space between them about twice that of one ramus width; armed with seven elements (three lateral, one dorsal and three apical). Ornamentation consists of large lateral cuticular pore near posterior margin, and posterior ventral row of several spinules along posterior margin. Dorsal seta slender and smooth, inserted closer to inner margin at about three-quarters of ramus length, about 0.8 times as long as caudal ramus, triarticulate (inserted on two small pseudojoints). 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. Dorsal anterior lateral seta longest, half as long as ramus, 1.4 times as long as ventral anterior seta, and about nine 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 1.7 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 0.8 times as long as ramus, inserted close to dorsal surface and pointing laterally.  
Antennula (Figures 1E,F, 5A) slightly longer than cephalothorax, slender, eightsegmented, prehensile and strongly digeniculate, ornamented with four ventral spinules on first segment distally, and with ribbed elongated chitinous plate on anterior surface of sixth segment. First segment very short whereas second segment longest. Geniculation between third and fourth and between sixth and seventh segments; last two segments in line. Distal anterior corner of seventh segment produced into very small spiniform process, but larger proximal spiniform process present on fifth segment on anterior surface. Massive aesthetasc on fifth segment reaching beyond tip of appendage, fused basally to slightly shorter seta, with nipple distally; much shorter and more slender apical aesthetasc on seventh segment, fused basally to two setae (acrotheck). Armature formula: 0.6.4.2.6 + ae.1.1.9 + ae. All setae slender and all smooth, except largest seta on second segment and proximalmost seta on fifth segment; most setae with pore on tip; most proximal seta on second segment longest and strongest, unipinnate with extremely long spinules along anterior surface.  
Antenna (Figures 1E, 5B) relatively stout and short, composed of coxa, allobasis, one-segmented endopod and one-segmented exopod. Coxa very short, unornamented. Allobasis about three times as long as wide, unarmed but ornamented with two rows of large spinules on anterior surface, and one short row of minute spinules on posterior surface. Endopod half as long as allobasis and twice as long as wide, with surface frill subdistally, ornamented with large spinules along anterior surface, armed laterally with two short spines (proximal one shorter) and apically with five strong elements (two geniculate). Exopod minute, cylindrical, about twice as long as wide, unornamented but armed with single apical seta, twice as long as segment. All antennal armature unipinnate.  
Labrum (Figures 1A, 6B) large and triangular in lateral view, trapezoidal in anterior view, with narrow and straight cutting edge, without any ornamentation on anterior surface, with several parallel rows of spinules along cutting edge (three on outer distal corners strongest and very broad, leaf-like).  
Paragnaths (Figures 1A, 6A) strongly fused into trilobate structure, with numerous distal rows of slender short spinules on lateral lobes, one distal row of minute spinules on central lobe, and another transverse row of 10 very long spinules on posterior surface of central lobe at about two-thirds of its length.  
 Mandibula (Figures 1A, 5C,D) with narrow cutting edge on elongated coxa, armed with one complex tooth ventrally, one unipinnate seta dorsally, and several smaller teeth and / or spinules in between. Palp one-segmented, cylindrical, about 2.5 times as long as wide, unornamented, and armed apically with two smooth and subequal setae, each with pore on tip.   
Maxillula (Figures 1A, 5E) with relatively large praecoxa, arthrite rectangular, about 1.5 times as long as wide from lateral view, ornamented with single spinule on posterior surface near dorsal margin, armed with lateral strong seta and four apical elements (probably three spines and one strong seta; apical spines with crown of spinules on tip, resembling small hands). Coxal endite armed with one smooth seta apically. Basis slightly longer than coxal endite, armed with three apical setae (two smooth and slender, one curved and unipinnate), and single minute lateral seta. Endopod and exopod absent (fused to basis without trace), minute seta on basis probably representing remnants of exopodal armature. All coxal and basal setae, as well as smooth lateral seta on praecoxa, with pore on tip.  
Maxilla (Figures 1A, 5F), composed of syncoxa, basis, and one-segmented endopod, ornamented with row of five spinules on inner side of syncoxa proximally, and with arched row of six spinules on posterior side of syncoxa close to outer margin. Syncoxa with two endites, basal armed with single smooth seta apically, distal armed with two smooth and one pinnate seta apically. Basis drawn out into strong and unipinnate claw, without seta at base, with cuticular pore on convex margin near distal tip. Endopod represented by minute segment, armed with two smooth subequal apical setae. All setae on maxilla with pore on tip.  
Maxilliped (Figures 1A, 5G) with short and relatively strong syncoxa, unarmed and unornamented; basis slender, almost five times as long as wide and three times as long as syncoxa, unornamented and unarmed; endopod represented by short curved claw, swollen at base as indication of ancestral one-segmented endopod, ornamented with several strong spinules along concave margin distally, about 0.7 times as long as basis.  
First swimming leg (Figures 1A, 6C) with smooth praecoxa, coxa and intercoxal sclerite. Praecoxa partly fused to coxa. Intercoxal sclerite very small, with narrow and concave distal margin. Basis somewhat shorter than coxa, pentagonal, ornamented with bunch of large spinules on outer margin, another bunch along distal margin at base of endopod, and armed with single short seta on outer margin. Exopod three-segmented, armed with one outer spine on first segment and four elements on third segment (two outer spines and two apical geniculate setae); ornamented with several large spinules along outer margin and distally on all segments. Endopod twosegmented, about as long as exopod; first segment reaching slightly beyond distal margin of second exopodal segment, about four times as long as wide, unarmed, ornamented with two short rows of large spinules on outer margin and one longer row of even longer spinules on inner margin; second segment armed apically with long geniculate seta and much shorter spine; endopodal geniculate seta 1.5 times as long as entire endopod, 1.2 times as long as larger geniculate exopodal seta, and almost 2.4 times as long as outer spine on endopod. All exopodal and endopodal armature unipinnate along outer margin.  
Second swimming leg (Figures 1A, 6D) with smooth praecoxa, and intercoxal sclerite. Intercoxal sclerite large, trapezoidal, with deeply concave distal margin. Praecoxa triangular and large. Coxa short, rhomboidal, with diagonal row of small spinules on anterior surface and two shorter rows of minute spinules along distal margin on posterior surface. Basis larger than coxa, semicircular, unarmed, ornamented with row of spinules on outer margin. Exopod three-segmented, ornamented with large spinules along outer margin, and with distal hyaline frills on each segment on inner side; first segment armed with single outer spine; second segment unarmed; third segment armed with three long elements (probably outer spine and two apical setae), innermost one slightly longer than exopod; all exopodal armature bipinnate. Endopod one-segmented, cylindrical and slender, almost five times as long as wide, reaching three-quarters of first exopodal segment in length, ornamented with four large spinules along apical margin; armed apically with single smooth seta, about 0.6 times as long as segment and pointing inwards.  
Third swimming leg (Figures 1B, 6E) with smooth intercoxal sclerite, larger than on other legs, trapezoidal, smooth, and with almost straight distal margin. Praecoxa not well defined on anterior surface, triangular on posterior surface, about as large as in second leg, unarmed, ornamented with single spinule on anterior surface. Coxa rectangular, with arched row of large spinules on anterior surface. Basis robust, ornamented with two minute spinules and one pore on anterior surface, several minute spinules along distal margin on posterior surface, armed with outer long and slender seta; distal inner corner of basis produced distally as short blunt chitinous beak, probably reinforcing exopod. Endopod represented by single smooth and strong armature element, inserted on inner margin at one-third of basis length. Exopod with both segments fused; ancestral proximal segment twice as long as wide, curved inwards and with inner chitinous bulge at two-thirds of its length, ornamented with several minute spinules along outer margin, and single small spinule on distal outer corner, armed subapically with simple, strong, smooth and inwardly curved spine, 1.6 times as long as apophysis; ancestral distal segment (apophysis) conical, oriented slightly inwards, unornamented, and armed with single short leaf-like seta on top with its tip pointing outwards.  
Fourth swimming leg (Figures 1C, 6F) with smooth praecoxa and intercoxal sclerite. Intercoxal sclerite shorter and smaller than in second leg, with equally long and concave distal margin. Praexoca, large and triangular from anterior view. Coxa rhomboidal, slightly smaller than in second leg, unarmed, ornamented with short distal row of spinules on posterior surface. Basis also short and rhomboidal in anterior view, armed with single outer seta, ornamented with several spinules on outer margin and with huge chitinous spiniform process between exopod and endopod, pointing inwards and leaf-like distally. Exopod three-segmented, ornamented with few large spinules along outer margin on all segments, and with hyaline frills distally on inner side of second and third segments; first segment with straight inner margin, additionally ornamented with long row of long and slender spinules along inner margin, armed with single outer spine; second segment unarmed; third segment armed with outer spine and long and strong apical seta; apical seta 2.7 times as long as third exopodal segment, 0.8 times as long as entire exopod, and more than twice as long as outer spine. Endopod shorter than spiniform process on basis, one-segmented and spiniform, with apical crown of four large spinules, fused basally and arranged as small scoop pointing outwards. Apical endopodal scoop and tip of basal hyaline spine forming pincer-like structure.  
Fifth leg (Figures 1D, 4B, 6G) simple elongated triangular plate, inner distal corner produced into very long and distally serrate spiniform process, ornamented with short row of six large spinules along inner margin, longer row of smaller spinules on posterior surface proximally, and cuticular pore on anterior surface, armed with three smooth setae; outermost seta (ancestral basal one) longest, almost as long as entire leg; middle seta (probably ancestral outer endopodal) much shorter than basal seta, hardly reaching tip of inner distal process, 0.2 times as long as leg, and 1.7 times as long as innermost seta (inner endopodal). Fifth legs distinct at base, with very small space between them, pointing caudally, and almost reaching distal margin of sixth legs with their tips.  
Sixth legs (Figures 1D, 6H) smooth, unarmed and unornamented, forming simple operculum covering gonopore, probably both fused together, or right one reduced and left one enlarged.  
 Female (based on allotype and several paratypes). Body length, excluding caudal setae, from 375 to 400 µm (385 µm in allotype). Habitus (Figure 2B), ornamentation of prosomites, colour and nauplius eye similar to male, except genital and first abdominal somite fused into double somite and habitus slightly less slender.   
Genital double somite (Figures 2B,E, 4C) 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 (Figures 2E, 6M) 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, hard to distinguish from internal tissue and gut content, rectangular; copulatory ducts weakly sclerotized. All posterior sensilla homologous to those on male third urosomite, while two sensilla from male second urosomite missing (nos. 32 and 34).  
Third, fourth (preanal) and fifth (anal) urosomites very similar to male (Figures 2 B–D, 4C).  
Caudal rami (Figures 2 B–D, 4C) slightly shorter in proportion to anal somite, about five times as long as wide in ventral (or dorsal) view, but also cylindrical and parallel or slightly divergent, with armature and ornamentation as in male.  
Antennula (Figures 2B, 5H) seven-segmented, ornamented on first segment with few minute spinules on ventral surface, not geniculate, with slender aesthetasc on fourth segment, not reaching beyond tip of appendage, and more slender apical aesthetasc on seventh segment, fused basally to two apical setae; proximal aesthetasc much more slender than in male; setal formula: 0.4.5.2 + ae.1.0.9 + ae. All setae, except proximalmost one on second segment, smooth, and most seta with pore on tip.  
Antenna (Figure 2B), labrum (Figure 2F), paragnaths (Figure 2F), mandibula (Figure 2F), maxillula (Figure 2F), maxilla (Figure 2F), maxilliped (Figure 2F), first swimming leg and second swimming leg (Figure 6I) similar to male.  
Third swimming leg (Figure 6J) with smooth praecoxa and intercoxal sclerite. Coxa with arched row of large spinules on anterior surface, and two rows of spinules along distal margin on posterior surface, unarmed. Basis ornamented with several spinules on outer margin distally, armed with very long and smooth outer seta about as long as entire exopod. Exopod two-segmented, ornamented with large spinules along outer margin, both segments with hyaline frills distally on inner side; first segment armed with single outer spine; second segment with outer spine and apical strong seta; all elements bipinnate. Endopod one-segmented, small, linguiform, unarmed, reaching only two-fifths of first exopodal segment in length, ornamented with three small distal spinules.  
Fourth swimming leg (Figure 6K) without spiniform process on basis. Endopod one-segmented, straight, ornamented with apical row of four spinules at base of apical spine and two spinules on inner margin; apical spine not distinct at base, smooth, and about 0.8 times as long as endopod; endopod with apical spine reaching posterior margin of first exopodal segment in length. Exopod similar to male, but inner margin of first exopodal segment lacks spinules.  
Fifth leg (Figures 2E, 4C, 6L) also represented by simple cuticular plate, but without any spinules along inner margin and with longer row of minute spinules on posterior surface proximally. Armature as in male.  
Sixth legs vestigial (Figures 2E, 6M), fused into simple cuticular flap, covering gonopores, unornamented and unarmed; distal margin thin, with produced lobe centrally and notches laterally.  
 Distribution   
This species is only known from the type locality, Young River near Sanggu city in South Korea (Figure 12).  
 Ecology   
Specimens were collected from the interstitial environment of the river bank sand, but no data are available on the water chemistry or sediment size.
description: Published as part of Karanovic, Tomislav, Cho, Joo-Lae & Lee, Wonchoel, 2012, Redefinition of the parastenocaridid genus Proserpinicaris (Copepoda: Harpacticoida), with description of three new species from Korea, pp. 1573-1613 in Journal of Natural History 46 (25 - 26) on pages 1579-1591, DOI: 10.1080/00222933.2012.681316, http://zenodo.org/record/4590799