Opisthopatus herbertorum, Ruhberg, Hilke & Hamer, Michelle L., 2005

Ruhberg, Hilke & Hamer, Michelle L., 2005, A new species of Opisthopatus Purcell, 1899 (Onychophora: Peripatopsidae) from KwaZulu­Natal, South Africa, Zootaxa 1039, pp. 27-38 : 29-33

Opisthopatus herbertorum sp. nov. ( Figs 1–2 ; 5–9; 11; 14)

Material examined. Holotype: Male. South Africa, KwaZulu­Natal, Mt. Currie Nature Reserve, near Kokstad, alongside road between main entrance and pass, in forest patch near ravine (30.28 713°S/29.22 781°E). Mist­belt afromontane forest. Collected from inside rotting log on steep forest floor, leg. R. Slotow, 6. VIII. 2002, fixed and det. H. Ruhberg, 20. IX. 2002 ( NMSA 20406).

Allotype: Female. South Africa, KwaZulu­Natal, Mt. Currie Nature Reserve, near Kokstad (30.28 713°S/29.22 781°E): patch of indigenous forest in ravine (dominated by Olinia emarginata ) in leaf litter, leg. D.G. Herbert, 3. V. 2000 ( NMSA 20407).

Diagnosis: Colour ± uniform white (= pearlwhite). Seventeen pairs of legs (= oncopods). Many (15) parallel complete dermal plicae/segment. Eyes present, but reduced. O. herbertorum distinguished from the other two Opisthopatus species by (a) number of legs: O. sp. nov. with 17 pairs, O. cinctipes with 16 pairs and O. roseus with 18 pairs; by (b) colour: O. roseus is a uniform dusky pink ( Fig. 3 ) and O. cinctipes never is concolourous, there are various colours including black, brown ( Fig. 4 ), orange, and green, and the species is dorsally speckled with lateral stripes above feet; occasionally collared forms occur. Eyes of O. herbertorum differ in size and shape from those of other Opisthopatus species ( Figs 13–14 ). Dermal plicae per segment more numerous in O. herbertorum (15 complete plicae) than in O. cinctipes (5–8 complete plicae and many anastomoses) and in O. roseus (8 complete plicae).

Description: Male (= Holotype): Distinct crural papillae on oncopods 6–15; crural papillae semicircular or dome­shaped, each with two proximal auricles. Anterior accessory papillae present on either side of genital pad. Paired posterior accessory papillae on anal cone. Genital pore cruciform ( Fig. 7 ).

Female (= Allotype): Specimen slightly perished; large wound between 6th and 7th pair of legs through which intestinal tract, parts of slime gland, and large parts of genital tract protrude. The latter filled with embryos in two different batches of developmental stages: (a) four undeveloped and (b) four and five well developed embryos in each uterus horn (sensu Curach & Sunnucks 1999). Those ready for birth display 17 pairs of legs (cf. stage b in: Curach & Sunnucks 1999). Crural papillae absent. Shape of genital pore: a horizontal and a smaller vertical slit, with tumid lips ( Fig. 9 ).

Dimensions: (a) Male: 24 mm long, 3.5 mm wide (fully extended drowned specimen, fixed in 70% ethanol), alive 36 mm length, when walking; (b) Female: 18 mm long, 2.5 mm wide (damaged specimen, fixed in 70% ethanol). Weight: Male: 0.144 g alive just before fixation.

Colour: uniform; whitish, with a suggestion of blue and pink (= pearl­white) ( Figs 1, 2 ).

Integument: Papillae numerous and closely packed; less variation in size and smaller than in O. cinctipes , 15 complete plicae per segment. Main (= primary) dermal papillae on dorsal surface of body low and rounded (smooth appearance) (Fig. 11), each with a prominent apical seta.

Head: Distinct dorsal cleft between antennae in both sexes, as in O. roseus (Fig. 16). Antennae with 30 complete rings each. Distal antennal chemoreceptors surrounded each by a circle of triangular teeth ( Fig. 15 ). Eyes reduced, shape distinctly elongated ( Fig. 13 ). Jaws: 0­5­5­0 (zero tooth on each outer blade, 5 teeth on each inner blade; see Ruhberg 1985).

Legs (= oncopods): 17 pairs in both sexes ( Figs 1, 2 ) with last pair only slightly reduced ( Fig. 7 ). Spinous pads: middle one larger than first and third. Nephridiopore of 4th and 5th leg divides third spinous pad into two subequal parts.

Crural papillae: Well developed and everted in drowned male specimen; occurring ventrally on legs 6–15. Semicircular or dome­shaped, each with two proximal auricles. Not present in female.

Accessory gland papillae: Flatter than crural papillae. (a) Anterior accessory gland papilla on each side of the genital pad; (b) paired posterior accessory gland papillae on anal cone; foramina separate ( Fig. 7 ).

Anal cone: Well developed, broad and plateau­shaped, not fully extended in holotype ( Fig. 7 ). Dermal papillae of anal cone differing from general body dermal papillae, with multiple scales nearly two­tiered.

Spermatophores: Not yet known.

Distribution: KwaZulu­Natal; at present only known from the type locality (Figs 5–6), a small (approximately 1 hectare) patch of forest in a gully in grassland, with nearest patches of similar forest estimated to be five to ten kilometers away.

Etymology: The name honours two persons; (a) Dr David G. Herbert (NMSA), who was the first to collect a specimen of this new species, and whose accurate GPS data greatly facilitated the finding of the second specimen; (b) Herbert Frese, the senior author’s father, who was killed, aged only 26, in the Second World War.

Figures

FIGURES 1 – 4. South African Opisthopatus species in culture. 1 – 2, O. herbertorum sp. nov. 1, Male. 2, Preserved injured female; wound (white arrow) where the intestines discharged, i = intestine / gut (black arrow), slg = slime gland, em = embryo, u = uterus. 3, O. roseus, Inset, enrolled position. 4, O. cinctipes, this morph lacks lateral stripes. FIGURE 5. Map of South African provinces, showing distribution of the three Opisthopatus species. FIGURE 6. Habitat of O. herbertorum, Mt. Currie Nature Reserve, forest patch in ravine in which specimens were collected. (Photograph 1 ­ 4, and 6 by H. Bosch, H. Ruhberg, and U. Sellenschlo).

FIGURES 13, 15. O. herbertorum sp. nov. 13, Eye. 15, Distal antennal chemoreceptor. FIGURES 14, 16. O. roseus 14, Eye. 16, Male. Dorsal cleft between antennae.

FIGURES 7, 9, 11. O. herbertorum sp. nov .. Morphological features, Drawing (7) and SEMs (8 ­ 16). 7, Posterior region of male body, ventral view. 9, Female genital pad. 11, Dorsal primary papilla. FIGURES 8, 10. O. cinctipes. Posterior ventral body region of male. FIGURE 12. O. cinctipes. Dorsal body primary papilla. acpa = anterior accessory papilla; acpp = posterior accessory papilla; an = anus; cp = crural papilla; dpp = distal oncopod papilla; gp = genital pad.