Johora gapensis ( Bott, 1966 )

Ng, Peter K. L., , Martyn E. Y. Low, Clark, & Paul F., 2022, Historical notes on various collectors of unidentified freshwater crabs (Crustacea: Decapoda: Brachyura) from the Malay Peninsula and Borneo, with descriptions of two new species of Isolapotamon Bott, 1968 Potamidae), Raffles Bulletin of Zoology 70, pp. 550-571 : 555

Johora gapensis ( Bott, 1966)

Potamiscus (Johora) johorensis gapensis Bott, 1966: 494 , text-fig. 31, pl. 21, fig. 14.

Material examined. 1 female ( NHM 2022.166 ), Camp 2, 3º51′30″ N 102º10′30″ E, 488 m asl, Gunung Benom, Pahang, Peninsular Malaysia, coll. A.G.C. Grandison & F. V. Slade , British Museum / University of Malaysia Expedition (February–April 1967), 12 March 1967 .

Remarks. Johora gapensis is morphologically close to J. intermedia Ng, 1986 , and the distributions for both species often overlap, especially at higher altitudes. At altitudes above 1000 m asl, only J. gapensis usually occurs (see Ng, 1987a, 1988, 2020). The most reliable diagnostic character is the structure of the G1 terminal segment, which in J. gapensis is elongate and sickle-shaped ( Ng, 1987a: fig. 2I, J) (vs. G1 shorter and more gently curved in J. intermedia ; Ng, 1987a: figs. 3, 4). The present specimen is a female so its species identity cannot be determined with certainty, but based on its presence in high altitudes, relatively small size (carapace width about 10 mm or less) and the fact that its already mature, suggests its more likely to be J. gapensis (see Ng, 1987 a, 2020).

Bott (1966) consistently spelled the specific name as “ gapensis ” in his original paper, but in his book ( Bott, 1970) he changed the spelling to “ gapiensis ” throughout the text without any explanation. Subsequent authors (e.g., Ng, 1987a, 1988, 2020) have used the original spelling.