Proserpinicaris corgosinhoi, Totakura, Venkateswara Rao, Reddy, Yenumula Ranga & Shaik, Shabuddin, 2014

Totakura, Venkateswara Rao, Reddy, Yenumula Ranga & Shaik, Shabuddin, 2014, Three new species of Parastenocarididae (Crustacea, Copepoda, Harpacticoida) from India, Zootaxa 3821 (5), pp. 501-537 : 514-526

Proserpinicaris corgosinhoi n. sp.

( Figs 9–14 )

Type locality. Same as that of Parastenocaris edakkal n. sp.

Type material examined. Holotype male, dissected on 2 slides (MNHN-IU-2013-11249), allotype female, dissected on 3 slides (MNHN-IU-2013-11250); 10 paratypes: 1 male (MNHN-IU-2013-11251) and 1 female (MNHN-IU-2013-11252), whole-mounted on 1 slide each, 1 male and 5 females preserved in alcohol (MNHN-IU- 2013-11253), and 1 male and 1 female in first author’s personal collections; 9 May 2008; Coll. V. R. Totakura & Y. Ranga Reddy.

Description of adult male. Total body length, measured from tip of rostrum to posterior margin of caudal rami (excluding caudal setae) 346 Μm. Preserved specimens colourless. Naupliar eye absent. Habitus ( Fig. 9 a) cylindrical and slender; prosome/urosome ratio about 0.8 in dorsal view; greatest width in dorsal view at subdistal cephalothorax. Body length/width ratio about 7.9. Free pedigerous somites without any lateral or dorsal expansions. All segments connected by well-developed arthrodial membranes. Hyaline fringes of all somites smooth, very narrow. Integument sclerotized, smooth, ornamented with sensilla, spinules, pores, and with somewhat subquadrate double-window in posterior half of cephalothorax, and elliptical, slender, dorsal simple cuticular window each on genital and 2 postgenital somites. Pleural areas of cephalothorax and free pedigerous somites well developed; cephalic appendages and coxae of swimming legs clearly exposed in lateral view (not figured). Rostrum ( Figs. 9 a, 10a) small, linguiform, not demarcated at base, ornamented with 2 large dorsal sensilla, reaching midlength of first antennular segment, about 1.2 times as long as wide. Cephalothorax ( Fig. 9 a) elongately oval in outline, with subdistal region dilated, about 1.4 times as long as wide in dorsal view and representing 21.5% of total body length. Surface of cephalic shield ornamented with subquadrate integumental double-window and 8 pairs of sensilla. Second and third pedigerous somites as wide as fourth pediger; fourth pediger longer than third one, and free pedigers 2–4 and first urosomite with 2 pairs of posterior sensilla each ( Fig. 9 a); first urosomite shorter than fourth pediger; genital somite widest of all urosomites, with small elliptical dorsal cuticular window in anterior half. Third urosomite as long as second one, with wider elliptical window and 3 pairs of sensilla. Fourth urosomite about as long as second urosomite, with dorsal cuticular window and 3 pairs of large posterior sensilla. Preanal somite narrower and slightly shorter than fourth urosomite, with largest dorsal cuticular window, extending latero-ventrally. Anal somite about as long as wide and slightly narrower than preanal somite, ornamented with 1 pair of large dorsal sensilla near base of anal operculum, 1 pair of large lateral cuticular pores in anterior half and 1 row of spinules on either side proximo-ventrally. A single large, longitudinally placed spermatophore discernible through cuticle of fifth and genital somites, about 2.1 times as long as wide, beanshaped, with narrow neck. Anal operculum well developed, smooth and bowl-shaped, with slightly concave distal margin, representing 59.1% of somite's width. Anal sinus wide and smooth.

Caudal rami ( Fig. 9 a–c): short, about 1.3 times as long as greatest width in dorsal view, 1.2 times in lateral view ( Fig. 9 b), and about 0.4 times as long as anal somite, proximal third slightly dilated; divergent, with space between them being about 1.2 times as long as that of 1 ramus maximum width; armed with 6 elements (2 lateral, 1 dorsal, 1 subapical, 2 apical); and ornamented with 1 row of spinules, and 1 cuticular pore disto-laterally; setae I and III thin, unequal, inserted at 2/5 of ramus; seta II missing. Dorsal seta (VII) slender and inserted close to inner margin in distal half, about 1.8 times as long as caudal ramus, biarticulate basally. Inner apical seta (VI) smooth, proximally swollen, inserted close to ventral margin, about 1.5 times as long as ramus length. Middle apical seta (V) strongest, without breaking plane, bipinnate, about 8.8 times as long as ramus, pointing distally, with straight, acute tip. Outer subapical seta (IV) without breaking plane and unipinnate, about 2.2 times as long as ramus, inserted close to dorsal surface and pointing laterally.

Antennule ( Fig. 10 b, c): 1.2 times as long as cephalothorax, stout, 8-segmented, strongly prehensile and digeniculate, proximal geniculation between third and fourth, and distal geniculation between sixth and seventh segments. First segment short, ornamented with 1 row of spinules. Second segment relatively short, about as long as fifth segment. Segments 4–5 much dilated, fifth segment with elongate, aesthetasc with narrow, blunt tip, reaching midlength of ultimate segment, fused basally to simple seta; apical aesthetasc on eighth segment slender, shorter than segment, fused basally with 2 setae (acrotheck). Setal formula: 0.6.4.2.8+aes.2.0.9+aes. All setae slender, smooth except proximalmost seta on second segment unipinnate with long setules. Length ratios of antennular segments from proximal to distal end along caudal margin 1:2.3:1.1:0.8:2.3:1.1:1.3:1.1.

Antenna ( Fig. 10 d): composed of coxa, allobasis, 1-segmented endopod, and 1-segmented exopod. Coxa short, ornamented with 1 row of short spinules, unarmed. Allobasis about 3.2 times as long as maximum width, unarmed, ornamented with 2 rows of spinules on inner margin. Exopod small, cylindrical, about thrice as long as wide, unornamented, armed with 1 unipinnate apical seta, which is about twice as long as segment. Endopod 0.7 times as long as allobasis and about twice as long as wide, with surface frill distally, ornamented with 2 longitudinal rows of spinules on inner margin and 2 rows of spinules distally; and armed with 2 unequal, bipinnate spines laterally and with 5 strong elements apically (2 spines, 2 geniculate setae and 1 unipinnate transformed seta).

Labrum large and subtriangular in lateral view, other details not studied (not figured).

Mandible ( Fig. 10 e): with narrow cutting edge on elongated coxa, armed with 2 complex teeth ventrally, 1 unipinnate seta dorsally, and several smaller teeth. Palp 1-segmented, cylindrical, about 3.2 times as long as wide, unornamented and armed with 2 smooth, unequal apical setae.

Maxillule ( Fig. 10 f): arthrite sub-rectangular, about 2.2 times as long as wide in lateral view, armed with 1 strong lateral seta and 3 apical elements. Coxal endite armed with 1 smooth apical seta. Basis twice as long as coxal endite, armed with 2 smooth apical setae.

Maxilla ( Fig. 10 g): composed of syncoxa, basis, and 1-segmented endopod. Syncoxa with 2 endites; basal one short, armed with 1 smooth seta apically, distal one long, armed with 1 smooth and 1 pinnate setae apically. Allobasis prolonged into strong unipinnate claw, without seta at base; endopod smallest, armed with 2 setae.

Maxilliped ( Fig. 10 h): with short syncoxa, unarmed and unornamented; basis slender, 2.3 times as long as wide, unornamented and unarmed; endopod small with unipinnate claw.

Swimming legs ( Figs. 11 a–b, 12a–d): praecoxa and intercoxal sclerite of all legs smooth and unarmed.

Leg 1 ( Fig. 11 a): coxa unarmed, ornamentation not discernible. Basis trapezoidal, ornamented with 1 row of large spinules on outer margin, and 1 row at base of endopod ventrally, armed with small, smooth outer seta. Exopod 3-segmented, ornamented with 1 row of spinules each along outer margins of all segments; armed with outer bipinnate spine on first segment. First segment 0.6 times as long as next 2 segments combined; second segment unarmed; 4 elements on third segment (1 outer spine, 1 apical seta and 2 apical geniculate setae). Endopod 2-segmented, first segment 3.3 times as long as wide, unarmed, ornamented with 1 row of spinules on inner margin and 1 ventral row of large spinules on outer margin, 1 row distally; second segment ornamented with spinular row on distal margin, armed apically with 1 outer spine and 1 long geniculate seta; endopodal geniculate seta 1.4 times as long as entire endopod, almost twice as long as outer spine, about as long as inner geniculate seta on exopod. All exopodal and endopodal armature elements unipinnate along outer margins except bipinnate spine on first exopodal segment.

Leg 2 ( Fig. 11 b): coxa ornamented with 1 arched row of spinules near outer margin and 1 oblique row medially near distal margin. Basis slightly smaller than coxa, unarmed, ornamented with 1 row of large arched spinules at distal outer corner and 1 pore proximally. Exopod 3-segmented; ornamented with 1 row of spinules each along outer margins of all segments, hyaline frill each at inner distal corner of first and third exopodal segments but second segment with 1 row of spinules instead. First segment 0.6 times as long as next 2 segments combined, armed with large, outer spine on first segment; second segment unarmed; third segment slightly longer than second segment, armed with 3 long elements (1 subapical unipinnate spine and 2 apical bipinnate setae); inner apical seta about 1.2 times as long as exopod. Endopod 1-segmented, cylindrical, and 3.2 times as long as wide, 0.4 times as long as first exopodal segment, ornamented with 2 large spinules apically on distal margin, 3 small spinules on inner margin and 2 spinules at midlength ventrally; armed apically with 1 smooth, straight seta, which is 0.9 times as long as segment.

Leg 3 ( Fig. 12 a–c): coxa trapezoidal, ornamented with arched row of ventro-medial spinules close to middistal margin. Basis produced disto-medially into 1 lobed structure; ornamented with 1 oblique row of long spinules and 1 pore on anterior surface. Endopod represented by a short spiniform seta at about proximal third of basis length. Exopod modified, both segments fused; ancestral proximal segment stumpy, with almost straight outer margin, 1.5 times as long as wide, about as long as basis, somewhat bent inwards, ornamented with 1 row of 3 spinules on distal outer margin. A massive tubular pore arising from proximal anterior surface. Ancestral second segment mace-like in anterior view ( Fig. 12 b), membranous, dilated subdistally, with irregular lateral margins, unornamented. Thumb dagger-shaped, gradually tapering, with acuminate tip and irregular hyaline membrane laterally ( Fig. 12 c).

Leg 4 ( Fig. 12 d–f): coxa trapezoidal, ornamented with 1 row of spinules near distal margin. Basis longer than coxa and trapezoidal in posterior view, ornamented with 1 row of spinules on outer margin and 1 pore proximally, armed with moderately long seta on outer margin. Exopod relatively short and thick, 3-segmented; ornamented with 1 row of spinules each along outer and inner margins of all segments; inner spinules on first segment particularly long; hyaline frill at inner distal corner of third segment. First segment 0.7 as long as next 2 segments combined, armed with 1 strong bipinnate outer spine subdistally; second segment unarmed and with straight inner margin; third segment slightly longer than second one, armed with 1 subapical spine and 1 apical bipinnate seta; apical seta 1.8 times as long as outer spine, about 1.7 times as long as third exopodal segment, half as long as entire exopod. Endopod short, membranous and somewhat conical, and additional hyaline structure relatively large, foliaceous and occurring rather close to, and partially overlapping, endopod.

Leg 5 ( Figs. 9 b, c, 11c): both legs fused at base, with narrow space proximally; represented by subquadrate plate, with distal inner corner rounded; ornamented with 1 row of spinules along distal half of inner margin, gradually increasing in size distally and 1 small cuticular pore on proximal surface; armed with 3 elements: 1 long articulate basal seta and 1 outer smooth, outcurved, simple seta, slightly shorter than inner spiniform seta (possible ancestral endopod).

Leg 6 ( Fig. 9 b, c): smooth, unornamented, forming simple operculum covering gonopore, fused with sixth pediger, and plate-like structure in ventral view.

Description of adult female. Body length, excluding caudal setae 384 Μm. Habitus ( Fig. 13 a): ornamentation of prosomites, colour and naupliar eye similar to male, except genital and first abdominal somites fused into double-genital somite.

Genital double-somite: without any trace of subdivision, with oval dorsal cuticular window ( Fig. 13 b) in anterior half, ornamented with 1 sensillum on either side of cuticular window ( Fig. 13 b). Genital complex occupying anterior ventral half of genital double-somite; genital apertures paired, covered by vestigial sixth legs; copulatory pores median; seminal receptacles small, hard to distinguish from internal tissue and gut content; copulatory duct very short and weakly sclerotized. Preanal somite, anal somite and urosomites very similar to male.

Caudal rami ( Fig. 13 a–c): divergent, 0.4 times as long as anal somite, about 1.2 times as long as wide in lateral view ( Fig. 13 b), 1.4 times in dorsal and ventral views ( Fig. 13 a, c), with armature and ornamentation as in male, but inner apical seta (VI) slightly swollen at base.

FIGURE. 15. Proserpinicaris karanovici n. sp., (a) paratype male, habitus, lateral view; (b) holotype male, urosome, ventral view.

Antennule ( Fig. 10 i): 7-segmented, first segment with few minute spinules at outer distal corner in lateroventral view; slender, elongate aesthetasc on fourth segment reaching almost distal margin of ultimate segment; seventh segment with relatively slender and short apical aesthetasc, which is fused basally to 2 apical setae; setal formula: 0.4.4.3+aes.0.0.8+aes. All setae smooth except unipinnate proximalmost one on second segment. Proximal seta on second and ultimate segment with basal articulation. Length ratio of antennular segments, from proximal to distal end and along caudal margin 1:2.7:1.6:1.8:1.1:1.1:1.6.

Antenna, labrum, mandible, maxillule, maxilla, maxilliped, and leg 1 similar to male.

Leg 2 ( Fig. 14 b): exopodal segments same as in male. Endopod cylindrical, armed with seta, which is 1.5 times as long as segment and reaching distal margin of first exopodal segment; ornamented with 1 spinule on outer margin, and 3 spinules on distal margin.

Leg 3 ( Fig. 14 c): coxa with arched spinular row on anterior surface. Basis ornamented with 1 row of spinules on outer margin and 1 row near base of endopod and 1 pore; armed with very long and smooth outer seta, articulate at base, 1.2 times as long as entire exopod. Exopod 2-segmented, ornamented with large spinules along outer margin and 1 row at inner distal corner of first segment; second segment alone with hyaline frill at inner distal corner; first segment armed with outer spine; second segment with 1 outer spine and 1 apical strong seta; seta 1.6 times as long as spine; all elements bipinnate. Endopod small, 2.6 times as long as wide, only half as long as first exopodal segment tapering to pointed tip, ornamented with transverse row of tiny spinules subdistally.

Leg 4 ( Fig. 14 d): exopod similar to male. Endopod rather slender, lanceolate, 1.5 times as long as first endopodal segment, with apical spine fused at base and having sparse spinules on lateral margins; 1 circlet of 3 spinules occurring at midlength (base of fused apical spine), and 1 spinule on proximal outer margin.

Leg 5 ( Figs. 11 d, 13b, c): both legs fused at base with narrow inter-space proximally; each in the form of obovate plate, reaching midlength of next segment and ornamented with 1 row of spinules on inner margin, spinules increasing in size distally; basal seta long, articulate at base; distal margin armed with 1 bare outer seta and 1 bipinnate inner spine, seta about as long as spine; distal inner corner produced into somewhat elongate inner spiniform process.

Sixth leg vestigial.

Etymology. The new species is named in honour of Dr. P. H. C. Corgosinho, Universitário Frutal-MG in Brazil, a well-known authority on the Neotropical Parastenocarididae . The specific epithet is a noun in the genitive singular. Gender masculine.

Distribution. This species is only known from the type locality.

Ecology. This species was accompanied by Parastenocaris edakkal n. sp. and nematodes in very small numbers.

Figures

FIGURE 9. Proserpinicaris corgosinhoi n. sp., paratype male (a), holotype male (b, c): (a) habitus, dorsal view; (b) urosome, lateral view; (c) urosome, ventral view.

FIGURE 10. Proserpinicaris corgosinhoi n. sp., holotype male (a – h); allotype female (i): (a) rostrum, latero-ventral view; (b) antennule, ventral view; (c) antennule, lateral view (ornamentation and armature omitted); (d) antenna, lateral view; (e) mandible, lateral view; (f) maxillule, lateral view; (g) maxilla, lateral view; (h) maxilliped, lateral view; (i) antennule, lateral view.

FIGURE 11. Proserpinicaris corgosinhoi n. sp., holotype male (a – b), paratype male (c), paratype female (d): (a) leg 1, anterior view; (b) leg 2, posterior view; (c) leg 5, ventral view; (d) leg 5, ventral view.

FIGURE 12. Proserpinicaris corgosinhoi n. sp., holotype male (a, d), paratype male (b, c, e, f): (a) leg 3, anterior view; (b) leg 3, apophysis, anterior view; (c) leg 3, thumb, anterior view; (d) leg 4, posterior view; (e, f) leg 4 endopod, posterior view.

FIGURE 13. Proserpinicaris corgosinhoi n. sp., paratype female, (a, b); allotype female (c): (a) habitus, dorsal view; (b) urosome, lateral view; (c) urosome, ventral view.

FIGURE 14. Proserpinicaris corgosinhoi n. sp., allotype female: (a) leg 1, posterior view; (b) leg 2, posterior view; (c) leg 3, posterior view (arrowhead pointing to spinular row); (d) leg 4, posterior view.