Haplocyclops (Kiefercyclops) godavari, Totakura, Venkateswara Rao & Reddy, Yenumula Ranga, 2015

Totakura, Venkateswara Rao & Reddy, Yenumula Ranga, 2015, Groundwater cyclopoid copepods of peninsular India, with description of eight new species, Zootaxa 3945 (1), pp. 1-93 : 81-89

Haplocyclops (Kiefercyclops) godavari n. sp.

( Figs. 51–54 )

Type locality. River Godavari (water temperature 26°C; pH 7.5) at Bhadrachalam town (16°41′933.5″N, 82°03′945.5″E; elevation 10.8 m) in Khammam District, Telangana State, South India ( Fig. 1 ).

Type material examined. Holotype female (MNHN-IU-2013-11894), and allotype male (MNHN-IU-2013- 11895), dissected on 3 slides each; 8 paratypes: 1 female (MNHN-IU-2013-11896) and 1 male (MNHN-IU-2013- 11897), dissected on 3 slides each; 2 females (MNHN-IU-2013-11898–11899) and 2 males (MNHN-IU-2013- 11900–11901), whole-mounted on 1 slide each, 2 females, dissected on 3 slides each in senior author’s personal collection; 12 October 2008; Coll. V. R. Totakura.

Diagnosis. Very small cyclopinae, with almost harpacticoidal habitus and smooth integument. Genital doublesomite strikingly large compared with rest of urosome, swollen both proximo-laterally and ventrally, with copulatory pore and ovipores situated at 4/5 of double-somite length. Anal somite with large crescentic anal operculum, protruding beyond somite’s limit. Caudal rami about 1.5 times as long as wide, parallel; lateral seta inserted in proximal half almost dorsally. Antennule in female 11-segmented, without lateral seta on ultimate segment and with only 2 setae on segment 7; the same appendage 13-segmented in male, strongly digeniculate. Antenna 4-segmented, with setal formula 1.1.5.6. and without any seta representing exopod. Cephalic appendages with reduced armature and/or segmentation: mandibular palp completely absent; maxillulary palp 1-segmented, endopod not distinct at base with 2 setae; maxilla without lateral seta on basis; and maxilliped 3-segmented, armature formula: 1.1.2. Legs 1–4 without any coxal armature and with only outer seta on basis: exopod of legs 1 and 2 as well as endopod of leg 1, 2-segmented, while all other rami 1-segmented (although armature of exopods reflects ancestral 2-segmented condition, the same could not be traced on endopods); spine formula of second exopodal segment of legs 1–4 (ancestral in case of legs 3 and 4) 2.2.2.2 and setal formula 5.4.4.3. Leg 1 with inner seta on first endopodal segment. Leg 5 completely fused to somite, represented by 3 slender setae. Leg 6 distinct cuticular plate, armed with 2 tiny setae in both sexes.

Description of adult female. Total body length, measured from base of rostrum to posterior margin of caudal rami (excluding caudal setae), 280 Μm. Preserved specimens colourless. Naupliar eye absent. Body ( Fig. 51 a) slender, almost harpacticoidal, dorso-ventrally compressed, with prosome/urosome ratio 1.3 and greatest width at middle of cephalothorax.

Body length/width ratio 4.1. Cephalothorax about as wide as genital double-somite, not produced posterolaterally. Rostral projection ( Fig. 51 a) moderately developed, broadly triangular, furnished with 2 small sensilla. Free pedigerous somites 2–4 with rounded postero-lateral corners. Pseudosomite absent between prosome and urosome. Fifth pedigerous somite 0.7 times as wide as genital double-somite and with oblique lateral margins, ornamented with 4 sensilla. Cephalothorax 1.3 times as long as its greatest width and 32.2% of total body length. Hyaline fringes of all somites very narrow and smooth; ornamentation not discernible on urosomites 3 and 4. Arthrodial membranes well developed, making the whole body flexible. Strongly sclerotized joint (as pseudosomite) present between fifth pediger and genital-double somite. Genital double-somite huge (2.4 times as long as rest of abdomen, characteristic in shape), swollen both laterally and ventrally, 0.9 times as wide as long, ornamented with pair of dorsal sensilla. Copulatory pore ( Fig. 51 c) small, ovoid, situated near the level of leg 6; copulatory duct short and straight, medially dilated, straight and well sclerotized. Seminal receptacle small, representing 31.3% of double-somite’s length, with clear distinction between large anterior and small posterior expansions; both expansions semicircular. Ovipores ( Fig. 51 c) situated laterally at 4/5 of somite length, covered with reduced sixth legs. Third urosomite greatly telescoping into genital double-somite. Anal somite without ornamentation except for 2 small dorsal sensilla; operculum large, crescentic, smooth, 74% of somite’s width, and produced slightly beyond somite’s limit. Anal sinus wide and smooth.

Caudal rami ( Fig. 51 a–c): symmetrical, parallel and close to each other with narrow space between them and 0.8 times as long as anal somite; each ramus 1.7 times as long as maximum width, basal part much narrower than the rest of ramus. Dorsal seta 2.1 times as long as caudal ramus, 0.7 times as long as principal outer seta, inserted at 4/5 of ramus length and uniarticulate at base. Lateral seta arising from dorsal surface close to outer margin at 3/5 of ramus length and 0.6 times as long as maximum width of ramus in dorsal view. Outermost apical seta spiniform, about as long as ramus, inserted subterminally. Innermost apical seta slender and 0.4 times as long as outermost apical seta. Principal apical setae without breaking planes. Inner seta 1.3 times as long as outer seta, 0.4 times as long as urosome and 4 times as long as caudal ramus. All caudal setae plumose.

Antennule ( Fig. 52 a): 11-segmented, extending up to middle of cephalothorax, ornamented with 1 row of spinules at base of first segment. Setal formula: 6.3.4.1.2.0.2.1.2.2.5+aes. Lateral seta on ultimate segment absent. Segments 3, 7, 8 and 11 with 2, 1, 1 and 2 long pinnate setae, respectively. Length ratios of antennular segments along medial axis: 1.0: 0.2: 0.6: 0.2: 0.2: 0.3: 0.5: 0.5: 0.6: 0.5: 0.8. Probable segmental homology 1 (I–V), 2 (VI–VII), 3 (VIII–XI), 4 (XII–XIII), 5 (XIV), 6 (XV–XVI), 7 (XVII–XX), 8 (XXI–XXIII), 9 (XXIV), 10 (XXV), 11 (XXVI–XXVIII).

Antenna ( Fig. 52 b): 4-segmented, consisting of long coxobasis and 3-segmented endopod. Setal formula of endopod: 1, 1, 5 and 6. Coxobasis twice as long as wide, unornamented and armed with 1 bipinnate seta at inner distal corner; exopodal seta absent. First endopodal segment 1.6 times as long as maximum width, armed with 1 simple seta on mid-inner margin and ornamented with 1 row of spinules near outer margin; second endopodal segment 1.4 times as long as wide, armed with 5 unequal setae. Third endopodal segment with 6 unequal, simple setae; ornamented with minute spinules along outer margin.

Labrum ( Fig. 52 c): elliptical/trapezoidal, unornamented. Anterior edge slightly convex, with about 20 small, equal teeth between slightly produced triangular lateral corners.

Mandible ( Fig. 52 d): coxal gnathobase divided roughly into 3 groups of teeth; inner group of 3 large unequal teeth, innermost one being larger; middle group consisting of medium-sized teeth and a small sub-distal spinular row; distal group with 1 pinnate outermost seta and 2 long spinules on ventral surface.

Paragnaths ( Fig. 52 e): conical lobe, ornamented with spinules on both margins.

Maxillule ( Fig. 52 f): composed of praecoxa and 1-segmented palp. Praecoxal arthrite bearing 3 strong clawlike spinous processes and 1 stout plumose seta and 6 medial elements on ventral side, proximalmost one largest and plumose. Palp composed of coxobasis and endopod. Coxobasis with 3 medial setae (2 smooth and slender, 1 strong and bipinnate), smooth medial setae unequal and 1.3 times as long as bipinnate seta; endopod fused at base, with 2 smooth setae (1 apical and 1 subapical). Exopodal seta absent.

Maxilla ( Fig. 52 g): 4-segmented, consisting of syncoxa, basipod and 2-segmented endopod. Praecoxa fused with coxa to form syncoxa. Proximal endite of praecoxa robust, armed with 2 equal, unarticulated, pinnate setae; distal endite absent. Proximal endite of coxa with 1 bipinnate seta; distal endite fused at base, elongate and armed apically with 2 smooth, equal setae; coxa unornamented. Basis expanded into robust claw, ornamented with 1 row of spinules along inner margin and armed with 1 strong, pinnate seta as long as claw. Endopod 2-segmented; proximal segment armed with 2 robust setae of about same length; distal segment small, with 1 robust, unipinnate, apical claw and 2 slender, equal and smooth subapical setae.

Maxilliped ( Fig. 52 h): 3-segmented, composed of coxobasis and 2-segmented endopod. Coxobasis about 3.1 times as long as wide and armed with 1 bipinnate seta inserted on spinulose protuberance at inner distal corner. First endopodal segment 0.3 times as long as coxobasis and armed with 1 bipinnate seta at unornamented inner distal corner. Second endopodal segment small, armed with strong and unipinnate seta apically and shorter, smooth seta subapically.

Legs 1–4 ( Fig. 53 a–e): leg 1 relatively short; exopod of legs 1 and 2, as well as endopod of leg 1, 2-segmented; all other rami 1-segmented (armature of exopods reflects ancestral 2-segmented condition, but not clear on endopods) and fringed with hairs. Endopod nearly equal to exopod in length on legs 1 and 2, but appreciably shorter on legs 3 and 4. Second exopodal segment spine formula: 2.2.2.2, and setal formula: 5.4.4.3. Intercoxal plates on all legs with rounded small, smooth prominences. Outer seta on basis of leg 1 relatively long and pinnate distally. Coxal seta on legs 1–4 absent.

Armature formula of legs 1–4 (legend: same as that of Paracyclopina orientalis ):

Coxa Basis Exopod Endopod

1 2 1 2

Leg 1 0-0 0-1 0-0 4, 1+I, I 1 -0 1, 1+I, 1 Leg 2 0-0 0-1 0- I 3, 1+I, I - I+1, 1 Leg 3 0-0 0-1 0- I 3, 1+I, I - 1, I+ 1 Leg 4 0-0 0-1 0- I 2, 1+I, I - 1 +I Leg 5 ( Fig. 51 a–d): completely fused to somite, represented by 3 slender setae. Remnant of basal segment represented by barely visible elevation, bearing 1 plumose outer basal seta, about 2.2 times as long as others; 2 other setae (armature of ancestral distal segment) subequal and smooth.

Leg 6 ( Fig. 51 b, c): distinct, small cuticular plate, unornamented and armed with 2 smooth, short setae. Description of adult male. Total body length excluding caudal setae 277 Μm, paratypes 256–289 Μm. Habitus ( Fig. 54 a) slenderer than that of female. Prosome/urosome ratio 1.2, greatest width at posterior end of cephalothorax. Body length/width ratio 4.6. Cephalothorax about 1.2 times as wide as genital somite and 30.4% of total body length; fifth pedigerous somite somewhat expanded at midlength and 0.8 times as wide as genital somite. Genital somite ( Fig. 54 a, b, c) about as long as wide, with slightly curved lateral margins. Third and fourth urosomites and anal somite similar to female, but anal operculum not extending beyond posterior margin of somite. Caudal rami ( Fig. 54 a–c): similar to female.

Antennule ( Fig. 52 i): digeniculate, 13-segmented. Segments 1 and 3 each with 1 slender aesthetasc. Setal formula: 3+3aes.2.1.0.0.1.1.0.1.2.0.0.4. Other cephalic appendages and legs 1–5 as in female. Length ratios of antennular segments along medial axis: 1.0: 0.4: 0.1: 0.2: 0.2: 0.2: 0.5: 0.5: 1.0: 0.7: 1.0. Segments 3 and 7 each with 1 bipinnate seta. Segments 3, 9 and 11 with setae having articulate basal part.

Leg 6 ( Fig. 54 c): both legs partly fused medially; each leg large, cuticular plate-like, armed with 2 unequal setae.

Etymology. The specific epithet alludes to the River Godavari from which the new species is collected; proposed here as a noun in apposition to the generic name.

Distribution. Haplocyclops godavari n. sp. was collected only from the type locality.

Remarks. Because of the overwhelming resemblance of Haplocyclops (Kiefercyclops) godavari n. sp. with Haplocyclops (Kiefercyclops) fiersi , we initially mistook the former for the latter. Scrutinous examination, however, has revealed that the former is indeed a valid new species belonging to the subgenus Haplocyclops (Kiefercyclops) Karanovic & Ranga Reddy, 2005 . H. (K.) godavari n. sp. fulfills all the criteria of the subgenus Kiefercyclops as follows: coxobasis of antenna armed with only one seta; mandibular palp completely reduced; maxillulary palp 1-segmneted; maxilla without lateral small seta on basis; maxilliped 3-segmented; legs 1–4 without any coxal armature; leg 1 first exopodal segment unarmed; exopod of leg 3 as well as endopods of all legs have reduced armature. The only exception is that leg 6 of the new species is armed with two setae instead of one seta.

H. (K.) godavari n. sp. can be distinguished from both H. (K.) primitivus n. sp. and H. (K.) fiersi by several morphological characters (see Table 4 ).

Figures

FIGURE 1. Map showing the type localities of the cyclopoid species on the Indian peninsula.

FIGURE 51. Haplocyclops godavari n. sp., paratype female (a – c), holotype female (d). (a) habitus, dorsal; (b) urosome, dorsal; (c) same, lateral; (d) same, ventral.

FIGURE 52. Haplocyclops godavari n. sp., holotype female (a – h), allotype male (i). (a) antennule, lateral; (b) antenna, lateral; (c) labrum, ventral; (d) mandible, lateral; (e) paragnath, ventral; (f) maxillule, lateral; (g) maxilla, lateral; (h) maxilliped, lateral; (i) antennule.

FIGURE 53. Haplocyclops godavari n. sp., holotype female (a – d), paratype female (e). (a) leg 1, anterior; (b) leg 2, anterior; (c) leg 3, posterior; (d) leg 4, anterior; (e) endopod of leg 3, anterior.

FIGURE 54. Haplocyclops godavari n. sp., paratype male (a, b), allotype male (c). (a) habitus, dorsal; (b) urosome, dorsal; (c) same, ventral.

Tables

TABLE 4. Principal morphological differences between H. (K.) primitivus n. sp., H. (K.) godavari n. sp., and H. (K.) fiersi.

Characters	H. (K.) primitivus n. sp.	H. (K.) godavari n. sp.	H. (K.) fiersi
Body size: range in (Μm) ♀ ♂	318–347 338	262–302 256–297	287 242
Body form	cyclopiform	harpacticoidal	harpacticoidal
Genital double-somite L/W Genital double-somite vs. abdomen Width of cephalic shield vs. genital double- somite	0.9 1.6 1.4	0.9 2 1.1	1.2 1.5 1.8
Antennule Third segment: relative length of dorsal seta at outer corner Fourth segment: no. of setae Fifth segment: no. of setae Ninth segment: outer seta	long 2 2 present	long 2 1 present	short 0 1 absent
Maxillule Distal elements on coxobasis Endopod	3 (1 plumose, 2 setae) distinct at base, with 3 setae	3 (1 plumose, 2 setae) basally fused, with 3 setae	2 (1 plumose, 1 seta) represented by 2 setae
Leg 1 Inner seta on first endopodal segment Outer seta on exp-2 vs. spine length Inner seta length vs. spine Length	present long short	present equal long	absent long short
Leg 2 No. of endopodal segments	2	1	1
Leg 3 No. of exo- and endopodal segments each	2	1	1
Leg 4: endopod No. of segments Seta on outer margin Seta on inner margin	2 absent absent	1 absent present	1 present absent
Leg 6: no. of armature elements	3	2	1
Sexual dimorphism in leg 3	present	absent	present
Caudal rami L/W ratio	1.6–1.7	1.7	2.1
Anal operculum	moderate	moderate	well developed
Habitat	river bank	river bank	bore