Parastacus nicoleti ( Philippi, 1882 )

Ribeiro, Felipe Bezerra & Araujo, Paula Beatriz, 2024, Taxonomic review of the genus Parastacus Huxley, 1879 (Decapoda: Astacidea: Parastacidae) with description of five new species, Zootaxa 5455 (1), pp. 1-84 : 25-26

Parastacus nicoleti ( Philippi, 1882)

( Fig. 12 )

Astacus chilensis .—­ Nicolet 1849: 211 [not H. Milne-Edwards, 1837] Astacus Nicoleti Philippi, 1882: 624 . Astacus nicoleti .—­ Faxon 1914: 354. Astacus Ricoleti. —­ Philippi 1882:6 26 [erroneous spelling]. Parastacus nicoletii Faxon, 1898: 689 [junior objective synonym]. Parastacus nicoleti. —­ Ortmann 1902: 293.—­ Porter 1917: 98, fig. 61.—­ Bahamonde 1958: 183, figs. 1–17.—­ Riek 1971: 133.—­

Hobbs 1989: 80, fig. 372.—­ Buckup & Rossi 1993: 168, fig. 4.—­ Rudolph 2010: 37, fig. 1C, 2C.—­ Rudolph 2013b: 1488,

fig. 14.—­ Ríos-Escalante 2016: 121, fig. 3(4).—­ Crandall & De Grave 2017: 641.—­ Ribeiro & Araujo 2017: 394, figs.

1–4.—­ Rogers et al. 2020: 876 (key), fig. 23.60.—­ Huber et al. 2022: 275 (key).—­ De los Ríos-Escalante et al. 2022: 1129

(appendix), fig. 1k.—­ De los Ríos-Escalante et al. 2023: 110, fig. 1(1).—­ Huber et al. 2024: 13 (key).

Parastacus Nicoleti. —­ Porter 1904: 255.

Parastacus nicoletti .—­ Bahamonde 1951: 91 [erroneous spelling]

Neotype: Chile: one male Miraflores , Río Valdivia, XI/1957, coll. Killian (MNHNCL DEC–15001), designated by Ribeiro & Araujo (2017).

Diagnosis. Bahamonde (1958), Buckup and Rossi (1993) and Rudolph (2013).

Remarks. A neotype was designated by Ribeiro and Araujo (2017) based on the examination of specimens from the type locality deposited in the Museo Nacional de Historia Natural of Chile previously analyzed by Bahamonde (1958), who confirmed the validity of this species. The authors improved the species description with the inclusion of new drawings and morphological characters. Along with Ribeiro and Araujo (2017), Buckup and Rossi (1993) indicated that the lateral spines in telson are present in all species of Parastacus , except P. nicoleti . Telson without lateral spines is also found in the Australian genus Engaeus Erichson, 1846 . The complete mitogenome of P. nicoleti was sequenced recently and revealed a sister-group relationship with all other Australian parastacid crayfishes (Ji et al. 2020). In addition, molecular species delimitation approaches using one mitochondrial marker (COI) raised the hypothesis that P. nicoleti could be a species complex ( Amador et al. 2021), which should be further tested with more data in an integrative way. COI results were tested using genomic data (SNPs), corroborating the results of the single locus species delimitation study ( Amador et al. 2021).

Color of living specimens. Rostrum, cephalothorax anterior and lateral regions, dorsal pleon and tailfan reddish brown. Pereiopod pairs 2–5 and chelipeds reddish brown. Antennal flagellum dark blue ( Fig. 12B ) ( Rudolph 2010).

Habitat and Ecology. Vegas or hualves ( Fig. 12D ). This species occurs in underground waters in small valleys or depressions between mountains or topographic depressions, usually associated with perennial forests (Rudolph 2013). Individuals of Parastacus nicoleti build deep burrows with multiple entrance tunnels and conspicuous chimneys ( Fig. 13C ) (Rudolph 2013). Parastacus nicoleti can be identified as type 2 according to Horwitz and Richardson’s (1986) classification and the species can be considered a primary burrower based on Hobbs’ (1942) classification ( Ribeiro et al. 2020).

Distribution. Chile ( Ribeiro and Araujo 2017).

Figures

FIGURE 12. Parastacus nicoleti (Philippi, 1882). A—­ Specimen deposited in the UFRGS collection (UFRGS 2405); B—­ living specimen; C—­ chimney; D—­ habitat, Vegas or hualves in Chile. Photos B—­ D by Luis Amador.

FIGURE 13. Parastacus defossus Faxon 1898 (FC-UDELAR w/n): A—­ habitus, dorsal view; B—­ cephalon, dorsal view; C—­ cephalon, lateral view; D—­ first to third male pleonal pleura; E—­ tailfan. Scale bars: A, C, D, E—­ 10 mm; B, F, G—­ 5 mm.