Neoleptastacus, NICHOLLS, 1945

Sak, Serdar, Huys, Rony & Karaytuğ, Süphan, 2008, Disentangling the subgeneric division of Arenopontia Kunz, 1937: resurrection of Psammoleptastacus Pennak, 1942, re-examination of Neoleptastacus spinicaudatus Nicholls, 1945, and proposal of two new genera and a new generic classification (Copepoda, Harpacticoida, Arenopontiidae), Zoological Journal of the Linnean Society 152, pp. 409-458 : 434-435

GENUS NEOLEPTASTACUS NICHOLLS, 1945

The genus Neoleptastacus has had an intricate taxonomic history since its proposal by Nicholls (1945). It remained monotypic until Chappuis (1955), and not Kunz (1954), as claimed by Noodt (1955a), relegated it to a junior synonym of Arenopontia . This course of action was forecasted by Chappuis’ (1954b) statement that Nicholls’ new genus Paraleptastacus [sic] should be united with Arenopontia . Krishnaswamy (1957) argued against this inclusion, and maintained the validity of Neoleptastacus as a distinct genus; he also added a second species, Neoleptastacus secundus , from the Madras coast. Wells (1967) dismissed Krishnaswamy’s (1957) decision, and retained Neoleptastacus as a subgenus of Arenopontia . Following some initial criticism by Mielke (1982a), the subgeneric classification was abolished by Martínez Arbizu & Moura (1994), and Neoleptastacus was synonymized with Arenopontia . Huys et al. (1996b) and Bodin (1997) reinstated both subgenera, but Wells (2007) preferred to amalgamate them, and consequently synonymized Neoleptastacus for the third time. The genus is resurrected here and redefined to accommodate: (1) all species that have previously been allocated to the subgenus Neoleptastacus (see Karanovic, 2000); (2) Mielke’s (1985) Chilean species A. clasingi , A. pacifica , and A. spicata ; and (3) the two species formerly included in the genus Pararenopontia [ Pararenopontia breviarticulata ( Mielke, 1975) and Pararenopontia trisetosa ( Mielke, 1982a) ]. A detailed review of the genus, including new species and an updated key, will be published elsewhere (Sak, Huys & Karaytuǧ, in press b).

Diagnosis: Arenopontiidae . Urosomites: occasionally with conspicuous surface ornamentation ( Neoleptastacus clasingi , Neoleptastacus ornamentus , and Neoleptastacus reductaspina ). Anal somite: with ( acanthus lineage) or without (all other lineages) paired dorsolateral spinous processes. Anal operculum: sometimes with median extension. Hyaline frills of abdominal somites with rectangular digitate or nondigitate lappets. Caudal ramus: usually with dorsolateral spur near medial margin. P1 exopod: two- or three-segmented; exp-1 with/without outer spine; exp-3 (or exp-2 when exopod two-segmented) with one or two spine(s) and two geniculate setae. P1 endopod: not prehensile, at least as long as exopod; enp-2 with two geniculate setae ( Neoleptastacus speluncae and Neoleptastacus phreaticus ) or outer spine plus inner geniculate seta (all other species). P2–P3 endopods: one- or two-segmented. P3 endopod: with outer distal element usually fused at base. P4 endopod: with welldeveloped outer distal element (except in trisetosus lineage). Armature formula as follows:

Exopod Endopod

P2 0.0.021 0.(0–1)(1–2)0 or 110 P3 0.0.021 0.0(1–2)0 or 010

P4 0.0.(0–1)21 0.020

P3 endopod ♂: not sexually dimorphic. P5 with outer basal seta and between one and three discrete elements; innermost element fused to segment forming spinous process (weakly delimited in Neoleptastacus trisetosus ); length of process sometimes sexually dimorphic. P 6 ♂ with one or two seta(e).

Type species: Neoleptastacus spinicaudatus Nicholls (1945) (by monotypy).

Other species: Arenopontia australis Chappuis, 1952 = Neoleptastacus australis (Chappuis, 1952) comb. nov.; Arenopontia acantha Chappuis, 1954b = Neoleptastacus acanthus ( Chappuis, 1954b) comb. nov.; Arenopontia longiremis Chappuis, 1955 = Neoleptastacus longiremis ( Chappuis, 1955) comb. nov.; N. secundus Krishnaswamy, 1957 ; Arenopontia africana Chappuis & Rouch, 1961 = Neoleptastacus africanus (Chappuis & Rouch, 1961) comb. nov.; Arenopontia accraensis Lang, 1965 = Neoleptastacus accraensis ( Lang, 1965) comb. nov.; Arenopontia indica Rao, 1967 = Neoleptastacus indicus ( Rao, 1967) comb. nov.; Arenopontia ishikariana Itô, 1968 = Neoleptastacus ishikarianus (Itô, 1968) comb. nov.; A. (Neoleptastacus) africana f. angolensis Kunz, 1971 = Neoleptastacus angolensis ( Kunz, 1971) comb. nov.; Arenopontia gussoae Cottarelli, 1973 = Neoleptastacus gussoae ( Cottarelli, 1973) comb. nov.; Arenopontia trisetosa Mielke, 1982a = Neoleptastacus trisetosus ( Mielke, 1982a) comb. nov.; Arenopontia clasingi Mielke, 1985 = Neoleptastacus clasingi ( Mielke, 1985) comb. nov.; Arenopontia pacifica Mielke, 1985 = Neoleptastacus pacificus ( Mielke, 1985) comb. nov.; Arenopontia spicata Mielke, 1985 = Neoleptastacus spicatus ( Mielke, 1985) comb. nov.; Arenopontia chaufriassei Bodiou & Colomines, 1986 = Neoleptastacus chaufriassei ( Bodiou & Colomines, 1986) comb. nov.; Arenopontia ornamenta Mielke, 1987 = Neoleptastacus ornamentus ( Mielke, 1987) comb. nov.; Arenopontia reductaspina Mielke, 1987 = Neoleptastacus reductaspina ( Mielke, 1987) comb. nov.; Arenopontia (Neoleptastacus) phreatica Cottarelli et al., 1994 = Neoleptastacus phreaticus ( Cottarelli et al., 1994) comb. nov.; Arenopontia (Neoleptastacus) speluncae Cottarelli et al., 1994 = Neoleptastacus speluncae ( Cottarelli et al., 1994) comb. nov.; Arenopontia (Neoleptastacus) huysi Karanovic, 2000 = Neoleptastacus huysi ( Karanovic, 2000) comb. nov.

Species inquirendae: Arenopontia ? gussoae Cottarelli, 1973 sensu Mielke (1982b) ; Arenopontia ? ishikariana Itô, 1968 sensu Mielke (1987) .

Species incertae sedis: Arenopontia breviarticulata Mielke, 1975 (see below).