Carinocryptus semenyukae, Golovatch, 2018

Golovatch, Sergei I., 2018, Further notes on the millipede family Cryptodesmidae in Southeast Asia, with descriptions of a new genus and two new species from Indochina (Diplopoda: Polydesmida), Raffles Bulletin of Zoology 66, pp. 361-370 : 365-367

Carinocryptus semenyukae , new species

( Figs. 3–5 )

Material examined. Holotype male ( ZMUM), Vietnam, Gia Lai Province, Kon Ka Kinh National Park , 14°18′08″N, 108°26′41″E, 600–700 m a.s.l., mixed tropical forest, stream valley, steep slope, May 2017, leg. I.I. Semenyuk.

Paratypes: 1 male, 3 females, 2 juveniles ( ZMUM), same data, together with holotype .

Diagnosis. With the characters of the genus.

Name. Honours Dr. Irina Semenyuk , the collector.

Description. Length of adults ca 9 (male and two female paratypes) to 9.5 mm (male holotype and one female paratype), width of midbody pro- and metazonae 0.8 and 2.0 mm (male holotype and two female paratypes) or 0.9 and 2.1 mm (one female paratype), respectively. General colouration in alcohol uniformly light creamy brown to dirty brown, only head, venter and legs nearly pallid ( Figs. 3 , 4 ). Juveniles completely pallid.

Body with 20 segments. In width, head << collum <segment 2 <3 <4 = 14(15); thereafter body gradually tapering towards telson ( Figs. 3 , 4 ). Head densely setose nearly throughout, also densely microgranulate between and behind antennae; epicranial suture superficial, more distinct in vertigial region. Antennae very short and densely setose, clearly clavate, C-shaped ( Figs. 3D , 4B ); in length, antennomere 1 = 2 = 4 = 7 <3 = 6 <5; antennomeres 5 and 6 subequally high, each with a small, compact, apicodorsal group of minute bacilliform sensilla. Interantennal isthmus ca 1.8 times broader than diameter of antennal socket.

Tegument dull and clearly microgranulate almost throughout, only prozonae smooth and very finely shagreened; collum, following metaterga and dorsal surface of epiproct clothed with a cerotegument crust. Dorsum strongly and mostly regularly convex; paraterga largely set at about upper 1/3 of body, very strongly developed, beginning with collum, regularly declined ventrad much like dorsum ( Figs. 3 , 4 ). Collum flabellate, fan-shaped, completely covering the head from above, anterior half flattened and subhorizontal, posterior half regularly rounded and with 5–6 transverse, irregular rows of small, round, setigerous tuberculations; anterior margin regularly rounded, with 23 indistinct radii and 12+12 small, setigerous lobulations. Postcollum metaterga with an increasingly high and distinct axial rib, the latter microtuberculate on top and inclined increasingly caudad in segments 16–18 ( Figs. 3A , 4A ), a little higher in male compared to female. Postcollum paraterga very broad, mostly squarish, midbody ones about as broad as prozonae; anterior margin/shoulder always entire, mostly nearly straight and narrowly bordered, increasingly, but faintly curved caudad towards telson, with neither radii nor crenulations, anterolateral corner slightly rounded; lateral margin of each paratergum with three radii and four small, subequal, setigerous lobulations, caudal corner drawn increasingly behind posterior tergal margin only in segments 17–19; paraterga 19 produced as far behind as about halfway of epiproct. Caudal margins of paraterga both radiate and increasingly strongly lobulate laterad, typically with 4+4 setigerous lobulations on each side until bases of paraterga, regardless of caudolateral lobulations ( Figs. 3 , 4 ). Ventral sides of paraterga more sparsely microtuberculate and microgranulate than both dorsally and laterally. Dorsal parts of postcollum metaterga with three transverse, rather regular rows of small, setigerous, round tubercles/knobs extended until lateral margin. Tergal setae very short, light, pointed, often abraded, but usually well visible, 1/5–1/6 as long as metatergum. Neither pleurosternal carinae nor visible ozopores. Stricture dividing pro- and metazonae narrow and shallow, microgranulate like adjacent parts of metaterga. Limbus brush-like, very densely microspiculate ( Fig. 4B ). Epiproct ( Figs. 3A, C, D , 4 ) conical, microgranulate and microtuberculate as previous metazonae. Hypoproct semicircular, 1+1 caudal setae clearly separated, borne on knobs.

Sternites narrow and deep ( Figs. 3C, D , 2B ), densely setose, clearly broadened only between male coxae 7 and 9. Legs long and slender, slightly enlarged both in male and female, without modifications ( Figs. 3 , 4B , 5A ), almost as long as paratergal width; in length, tarsi = femora >> coxae = prefemora = postfemora = tibiae; gonapophyses on male coxae 2 small cones; neither adenostyles nor tarsal brushes. Claws simple, slightly curved ventrad ( Fig. 5A ). Gonopod aperture transversely ovoid, caudal and lateral margins thin and slightly elevated.

Gonopods ( Figs. 3D , 5B, C ) in situ held parallel to each other. Coxite typically short and irregularly subquadrate, distal part with a short, subtriangular, apicomesal lobe, ventroparabasal part microtuberculate and equipped with 1–2 strong setae; cannula as usual, slender, long and unciform. Telopodite subquadrate, stout, clearly bipartite. Basal branch (b) caudal in position, with a seminal groove running along mesal face before moving distolaterad onto a prominent, simple, retrorse, spiniform solenomere (sl). Part b suberect, subdivided into a prominent, rounded, “prefemoral” part, the latter devoid of any processes, densely setose on both sides and set off from a middle, laterally similarly setose and disk-shaped part by a lateral sulcus and a constriction, this part being crowned by sl. Distal part of b nearly fingershaped, high, rounded at apex and carrying a prominent, similarly rounded swelling (s), the latter overhanging laterad before sl base. Caudal branch an anterior solenophore (sph), slightly curved caudad, about as high as branch b, ribbonshaped, in distal half with two marginal hyaline membranes, including a rounded anterior lobe with a parabasal tooth (t) and a complex, strongly rugged, caudal lobe (l). An inconspicuous, but sufficiently evident node (a) at base of both l and t, this node a apparently representing an anlage of and homologue to an accessory seminal chamber, the latter lying on sph just opposite sl tip. A long and very distinct accessory seminal duct leading from a to an acuminate and anteriorly recurved sph tip.

Remark. Not only the accessory seminal chamber and duct, but even the hyaline lobes on the solenophore of Carinocryptus semenyukae , new species, are so strongly reminiscent of those in Circulocryptus spp. that these similarities are overwhelming and are simply impossible to neglect when uniting these two genera into a very distinct tribe (see above).

Figures

Fig. 3. Carinocryptus semenyukae, new species, male paratype. Habitus, A, lateral view; B, dorsal view; C, anteroventral view; D, posteroventral view. Pictures taken not to scale.

Fig. 4. Carinocryptus semenyukae, new species, male paratype. Habitus (segment 7 removed), A, dorsal view; B, ventral view. Pictures taken not to scale.

Fig. 5. Carinocryptus semenyukae, new species, male holotype. A, Leg 9, lateral view; B, left gonopod, mesal view; C, left gonopod, lateral view. Scale bars = 0.1 mm. Designations: a = anlage of an accessory seminal chamber; b = basal branch; d = seminal duct; e = retrorse tip of seminal duct; l = rugged caudal lobe; s = apical swelling of basal branch; sl = solenomere; sph = solenophorous branch; t = tooth on anterior lobe.

Fig. 2. Circulocryptus kompantsevi, new species, holotype. A, Leg 9, lateral view; B, right gonopod, lateral view; C, right gonopod, mesal view. Scale bar = 0.1 mm (A) and 0.2 mm (B, C). Designations: a = accessory seminal chamber; b = basal branch; l = hyaline fringed lobe at base of solenomere; p = prefemoral process; sl = solenomere; sph = solenophorous branch.