Scorpiones (Prendini, 2005)

Haddad, Charles, Prendini, Lorenzo, Neethling, Jan-Andries & Dippenaar-Schoeman, Anna Sophia, 2023, The non-acarine Arachnida of the Amathole Mountains, South Africa, Bothalia (a 13) 53 (1), pp. 1-33 : 11

Scorpiones (scorpions)

Eight species, representing six genera and three families of scorpions have been recorded in and around the Amathole Mountains ( Table 1; Supplementary Table 1). These include three species of thick-tailed scorpions (genera Parabuthus Pocock, 1890 and Uroplectes Peters, 1861 ) in the family Buthidae , one species of flat rock scorpion (genus Hadogenes Kraepelin, 1894 ), three species of creeping scorpions (genera Cheloctonus Pocock, 1892 and Opisthacanthus Peters, 1861 ) in the family Hormuridae , and one species of burrowing scorpion (genus Opistophthalmus C. L. Koch, 1837 ) in the family Scorpionidae .

The scorpions of the Amathole Mountains may be classified into three ecomorphotypes ( Table 3) based on their morphology and microhabitat requirements ( Prendini 2001, 2005). The thick-tailed scorpions of the genus Uroplectes ( Figure 6E, F ) are lapidicolous, sheltering under stones, logs and other surface debris. These morphologically generalist scorpions are ecologically eurytopic. All other scorpion taxa occurring in and around the mountain range are morphologically specialist and ecologically stenotopic. The thick-tailed scorpion, Parabuthus planicauda (Pocock, 1889) ( Figure 6D ), is also fossorial and pelophilous, constructing scrapes or shallow burrows, usually under stones. The flat rock scorpion, Hadogenes trichiurus (Gervais, 1843) ( Figure 6G ), and one of the creeping scorpions, Opisthacanthus validus Thorell, 1876 ( Figure 6H ), are lithophilous, inhabiting the narrow cracks and crevices of rock outcrops. The burrowing scorpion, Opistophthalmus latimanus C. L. Koch, 1841 ( Figure 6I ), and the creeping scorpions of the genus Cheloctonus are fossorial and pelophilous, constructing burrows in hard, clayey soil, usually in open ground [ Cheloctonus crassimanus (Pocock, 1896) and O. latimanus ] or un- der stones ( C. glaber Kraepelin, 1896 ). The burrows of Opistophthalmus are usually constructed at an angle to the ground surface, with a semi-circular entrance opening, whereas the burrows of Cheloctonus are usually vertical, with a more slit-like entrance opening.

The method of burrow construction differs among the four fossorial scorpion taxa. The scorpionid, O. latimanus , is a cheliceral burrower, which uses the chelicerae to loosen the soil, and the legs and, to a lesser extent, the metasoma, to scrape it away. The hormurids, C. crassimanus and C. glaber , are pedipalpal burrowers, which use the pedipalps to loosen and scrape the soil away. The buthid, P. planicauda , is a metasomal burrower, which uses the metasoma to loosen the soil and the legs and metasoma to scrape it away.

Different scorpion taxa inhabit distinct geographical areas in and around the Amathole Mountains. Three species with lower tolerance for aridity occupy mesic

Opistophthalmus latimanus C.L. Koch, 1841 pelophilous savanna, thicket low valleys, S slope habitats at higher elevations on the mountain range. Opisthacanthus validus inhabits forests and thicket on the summit and southern slopes whereas C. glaber inhabits grasslands on the summit and northern slopes. Uroplectes formosus Pocock, 1890 inhabits grasslands and thicket on the summit, northern and southern slopes. Five species with higher tolerance for aridity occupy xeric habitats, primarily savanna, thicket and, in places, Nama Karoo, in the warm, dry valleys intersecting the mountains. Parabuthus planicauda and U. triangulifer (Thorell, 1876) occur in valleys intersecting both the northern and southern slopes of the mountain range, whereas C. crassimanus and O. latimanus are restricted to valleys intersecting the southern slopes and H. trichiurus to valleys intersecting the northern slopes.

Figures

Figure 6. Selected harvestmen and scorpions from the Amathole Mountains, Eastern Cape, South Africa; A, Rhampsinitus sp., male (Phalangiidae);B, Rhampsinitus aff.silvaticus, female (Phalangiidae); C, possible Adaeum sp., female (Triaenonychidae);D, Parabuthus planicauda, female (Buthidae); E, Uroplectes formosus, female (Buthidae); F, Uroplectes triangulifer, male (Buthidae); G, Hadogenes trichiurus, juvenile (Hormuridae); H, Opistacanthus validus, male (Hormuridae); I, Opistophthalmus latimanus, female (Scorpionidae). Photos: A–C, G, H, C. Haddad; D, C. Hobson; E, I, S. Christie; F, G. Diedericks.