Cryptops nigropictus Takakuwa, 1936

Cryptops nigropictus Takakuwa, 1936 View in CoL

Fig. 4 View Figure 4

Examined material.

12 specimens: NHMUK 015991424 , 3 specimens, Black Path , Picard, Aldabra, Summer 1975 ; NHMUK 015991426 , 3 specimens, Calophyllum litter, Takamaka , Grande Terre, 14. 01. 1975 ; NHMUK 015991427 , 2 specimens, Sideroxylon litter, Au Parc , Aldabra, 14. 02. 1975. V. W. Spaull leg ; NHMUK 015991428 , 1 specimen, Picard , Aldabra, 28. 02. 1975 ; NHMUK 015991445 , 1 specimen, Sideroxylon litter, Ile. Michel , Aldabra, 28. 03. 1975 ; NHMUK 015991446 , 2 specimens, Casuarina litter, Picard , Aldabra, 08. 05. 1974 .

Remarks.

Taxonomic revision of Cryptops species belonging to the “ hortensis group ” identified C. decoratus Lawrence, 1960 , C. melanotypus Chamberlin, 1941 , and C. nigropictus Takakuwa, 1936 as a potential species complex, raising doubts on the taxonomic validity of many morphologically similar species ( Lewis 2011). A reliable diagnostic trait mentioned by Lewis (2011) is the presence of a single long pretarsal accessory spur in C. nigropictus (Fig. 4 K View Figure 4 ), differentiating it from C. decoratus and C. melanotypus which bear two small pretarsal accessory spurs on leg pairs 1–20. The Aldabra specimens key out to C. nigropictus in the key provided within the same article and agree with its revised description. Although originally described from East Asia, various nominal taxa recorded from East Africa and islands of the Indian Ocean (including Mauritius and Rodrigues) have been placed in synonymy with C. nigropictus ( Lewis 2011) .

Cryptops daszaki Lewis, 2002 was described from several localities in Mauritius. Lewis (2002) remarked on the small body size (4.5–7.5 mm) of sexually mature specimens and their apparent juvenile characteristics (low number of coxal pores, reduced setation). The specimens collected from Aldabra with a similar body length to specimens assigned by Lewis to C. daszaki overlap in morphology with respect to the usual lack of subcuticular dark pigment, the number of setae on the anterior margin of the forcipular coxosternite (2 or 3 on each side in C. daszaki , 3 or 4 on each side in C. nigropictus ; Fig. 4 C View Figure 4 versus Fig. 4 A, B, D View Figure 4 , respectively), the relative length of the single pretarsal accessory spur on legs 1–20 (> 1 / 2 the length of the pretarsus) and the number of coxal pores (5 or 6 in C. daszaki , 4–9 in C. nigropictus ) but show greater variation than C. daszaki in the number of saw teeth on the tibia (3–5) and tarsus (2 or 3). The number of tibial and tarsal saw teeth is known to be intraspecifically variable in Cryptops ( Iorio and Geoffroy 2003; Lewis 2009) and scales allometrically with body size, as exemplified by the largest C. nigropictus specimen in our sample (12 mm, NHMUK 015991426 ; Fig. 4 I View Figure 4 ).

The only other diagnostic trait given by Lewis (2011) separating C. daszaki and C. nigropictus is the position of the setae near the anterior margin of the forcipular coxosternite, being described as “ marginal ” in C. daszaki and “ submarginal ” in C. nigropictus . Re-examination of the type specimens of C. daszaki revealed that these setae occupy a submarginal position (Fig. 4 C View Figure 4 ), which may be misinterpreted as marginal depending on the orientation of the specimens. As both of the two putative diagnostic traits separating C. daszaki and C. nigropictus are fully encompassed by intraspecific variation within C. nigropictus and the latter species has been recorded from nearby localities ( Lewis 2002), we consider C. daszaki a likely junior subjective synonym of C. nigropictus , from which it cannot be reliably distinguished by morphology alone. Similarly, the presence of subcuticular dark pigment cannot be reliably used to separate putative Cryptops species in Western Indian Ocean and Eastern African localities. This character is variable within our sample, with all specimens with the exception of NHMUK 015991428 lacking dark subcuticular pigment. Dark pigmentation is also variable in the type specimens of Cryptops niloticus Lewis, 1967 (present in male allotype but absent in female holotype and in juvenile paratype), a species previously recorded from the Western Indian Ocean ( Lewis 2002) but subsequently synonymised with C. nigropictus ( Lewis 2011) .