Neoleptastacus accraensis ( Lang, 1965 ), 2008

Sak, Serdar, Karaytuğ, Süphan & Huys, Rony, 2024, Review of Neoleptastacus Nicholls, 1945 (Harpacticoida, Arenopontiidae), including an updated key to species and proposal of Phreatipontia gen. nov., Zootaxa 5525 (1), pp. 1-66 : 44

Neoleptastacus accraensis ( Lang, 1965)

Arenopontia longiremis Chappuis, 1955 sensu Chappuis & Rouch (1961: 608)

Arenopontia accraensis Lang, 1965

Arenopontia (Neoleptastacus) accraensis Lang, 1965 : Wells (1967: 324 —spelled accraensis )

Arenopontia (Neoleptastacus) acantha accraensis Lang, 1965 : Kunz (1971: 356)

Neoleptastacus accraensis ( Lang, 1965) Sak et al. (2008: 412)

Original description. Chappuis & Rouch (1961 —as A. longiremis ): 607–608; Figs 9–13 (♀ only).

Type locality. Ghana, Greater Accra Region, Accra ; sandy beach in front of the lighthouse .

Body length. Unknown.

Remarks. Chappuis & Rouch (1961: 608, Figs 9–13 ) recorded two females from a sandy beach in Accra which they assigned to Arenopontia longiremis Chappuis, 1955 . They considered the differences with the type population as insignificant, being a likely reflection of the disjunct distribution of the species. Lang (1965) considered Chappuis & Rouch’s (1961) Ghanaian specimens to fall outside the limits of variability of A. longiremis and proposed a new name, A. accraensis , for them. Kunz (1971) treated A. longiremis and A. accraensis as subspecies of A. acantha but this was not adopted by subsequent revisers [ Itô 1978; Bodiou & Colomines 1986; Wells 2007; Sak et al. 2008 —but see Bodin (1997) for a dissenting opinion]. The Angolan material identified by Kunz (1971) as A. (N.) acantha accraensis belongs to a different species, described here as N. emendatus sp. nov. (see above).

Although Lang (1965), Bodiou & Colomines (1986) and Wells (2007) claim that P4 exp-3 possesses an inner seta, the setation of this leg has yet to be revealed. Similarly, in the identification keys provided by these authorities and Karanovic (2000) it is assumed that the distal endopod segment of P3 has only one distal element. However, Chappuis & Rouch (1961) show a second short element on enp- 2 in their illustration of the P3 endopod. This element is here interpreted as the outer distal spine using the spinule row on enp-1 as a reference point for correct orientation. Note also that Chappuis & Rouch’s (1961) illustration of the P1 shows it in an unnatural twisted position and that the terminal spinous process on the caudal ramus was figured as an articulating spine. The latter condition is unlikely since the caudal process in all members of the Arenopontiidae represents a posterior outgrowth of the ramus and not the homologue of an armature element that became secondarily incorporated.

Neoleptastacus accraensis is in need of detailed redescription (including the as yet unknown male) and is treated here as a species inquirenda in the genus since it is practically unidentifiable based on the few drawings provided by Chappuis & Rouch (1961). It is tentatively placed in the spinicaudatus -group based on the combined absence of paired anal processes and the retention of the plesiomorphic armature formula of P1–P4. The species is only known from the type locality where it occurs sympatrically with N. africanus .

Taxa of doubtful identity

Figures

FIGURE 9. Neoleptastacus supersetosus sp. nov. (♀): (A) habitus, lateral; (B) antenna, medial [lateral endopodal spines indicated by arrows]; (C) antennary endopod, outer [lateral spines omitted]; (D) P1, anterior; (E) P2, anterior [outer spine of exp-1 broken]; (F) P3, anterior; (G) P4, anterior.

FIGURE 10. Neoleptastacus supersetosus sp. nov.: (A) urosome (♀), ventral [arrow indicating copulatory pore]; (B) urosome (♂), ventral.

FIGURE 11. Neoleptastacus supersetosus sp. nov.: (A) habitus (♂), lateral; (B) rostrum and cephalothorax (♀), dorsal; (C) anal somite and caudal rami (♀), dorsal; (D) anal somite and left caudal ramus (♀), lateral; (E) antennule (♀), dorsal; (F) antennule (♂), dorsal.

FIGURE 12. Phreatipontia phreatica (Cottarelli, Bruno & Venanzetti, 1994) comb. nov. (♀): (A) habitus, lateral; (B) habitus, dorsal; (C) anal somite and caudal rami, dorsal [arrow indicating modified seta IV]: (D) anal somite and right caudal ramus, lateral.

FIGURE 13. Phreatipontia phreatica (Cottarelli, Bruno & Venanzetti, 1994) comb. nov.: (A) antennule (♀), dorsal; (B) antenna (♀), medial [lateral endopodal spines indicated by arrows]; (C) antenna (♀), outer; (D) antennule (♂), anterior; (E) antennule (♂), dorsal.