Pilumnopeus granulatus Balss, 1933

Ng, Peter K. L. & Lee, Sang-Kyu, 2025, On the identity of Pilumnopeus granulatus Balss, 1933 (Crustacea: Decapoda: Brachyura: Pilumnidae), and description of a new Pilumnopeus from Korea, Zootaxa 5642 (4), pp. 331-342 : 332-335

publication ID	https://doi.org/10.11646/zootaxa.5642.4.3
publication LSID	lsid:zoobank.org:pub:81633952-54E0-4356-9159-E2164C1E7372
DOI	https://doi.org/10.5281/zenodo.15601681
persistent identifier	https://treatment.plazi.org/id/03AEDF5D-BD28-7F27-FF45-FADDCDD7FB63
treatment provided by	Plazi
scientific name	Pilumnopeus granulatus Balss, 1933
status

Treatment

Pilumnopeus granulatus Balss, 1933 View in CoL

( Figures 2 View FIGURE 2 , 6C–D View FIGURE 6 , 7A–D View FIGURE 7 )

Pilumnopeus serratifrons granulatus Balss, 1933: 34 View in CoL .

Heteropanope (Pilumnopeus) serratifrons granulatus — Serène 1968: 87.

Pilumnopeus granulatus View in CoL — Takeda & Miyake 1969: 127 (part).— Ng et al. 2008: 141.

Material examined. Lectotype (herein designated): male (14.4 mm × 10.7 mm) ( ZMH K-001550), Viti Levu , Fiji (labelled as ex. Mus, Godeffroy MG 2232 ), coll. no information.

Diagnosis. Dorsal carapace surface with regions well defined, with numerous rounded granules, especially dense on posterior half of carapace, with dense, low pubescence between the raised regions ( Fig. 2A, B View FIGURE 2 ); frontal margin lined with prominent rounded granules ( Fig. 2D View FIGURE 2 ); posterior margin of epistome distinctly wide with a low obtusely triangular median lobe ( Fig. 2E View FIGURE 2 ); outer surfaces of cheliped covered with numerous flattened granules and short setae ( Fig. 2G View FIGURE 2 ); male pleon proportionately wider, with somite 6 wider than long, rectangular ( Fig. 6D View FIGURE 6 ); overall G1 relatively longer, relatively more slender ( Fig. 7A View FIGURE 7 ); G1 distal part less strongly curved with tip not reaching main stem; distal inner margin with 8 distinctly recurved spines ( Fig. 7A–C View FIGURE 7 ).

Remarks. Balss (1933: 34) named the taxon as a subspecies of P. serratifrons , noting that “Beide Tiere unterscheiden sich von den australischen Stücken durch ihre Scheren, welche auf der Aussenseite ziemlich stark granuliert sind, während bei den typischen Formen die Aussenseiten glatt sind und nur der Unterrand derselben granuliert ist.” [Both animals differ from the Australian specimens by their claws, which are quite strongly granulated on the outside, while in the typical forms the outside surfaces are smooth and only the lower edge is granulated.] Balss (1933) had two specimens, one male (14.0 mm × 11.0 mm) from Fiji and a smaller male (10.5 × 8.0 mm) from Great Harbour, in New Mecklenburg (= present day New Ireland Province), northeastern Papua New Guinea. Although the present specimen from Fiji is labelled as a “ holotype ”, it is not. Both of Balss’ (1933) original specimens are syntypes as he did not designate a holotype. The larger specimen, which is examined in the present study, is herein designated as the lectotype of Pilumnopeus serratifrons granulatus Balss, 1933 .

Pilumnopeus granulatus resembles P. serratifrons , but can readily be distinguished by the more strongly granulated dorsal carapace surface with dense, low pubescence between the raised regions ( Fig. 2A, B View FIGURE 2 ) (versus surface less granulated, with more scattered setae in P. serratifrons ; Fig. 1A, B View FIGURE 1 ); the frontal margin is lined with prominent rounded granules ( Fig. 2D View FIGURE 2 ) (versus with sharp granules in P. serratifrons ; Fig. 1D View FIGURE 1 ); the outer surfaces of the cheliped are covered with numerous flattened granules and very low setae ( Fig. 2G View FIGURE 2 ) (versus with low granules and is generally smooth and glabrous in P. serratifrons ; Fig. 1G View FIGURE 1 ); the male pleon is proportionately wider, with somite 6 wider than long and rectangular ( Fig. 6D View FIGURE 6 ) (versus pleon narrower, with somite 6 as long as broad and quadrate in P. serratifrons ; Fig. 6B View FIGURE 6 ); the overall G1 is relatively longer and more slender ( Fig. 7A View FIGURE 7 ) (versus relatively shorter and stouter in P. serratifrons ; cf. Davie 1989: fig. 5E); and the distal part of the G1 is less strongly curved with the tip not reaching the main stem ( Fig. 7A–C View FIGURE 7 ) (versus tip longer and overlaps the main G1 stem in P. serratifrons ; cf. Davie 1989: fig. 5E, F).

The strong granulation on the carapace and chelipeds of P. granulatus is somewhat similar to the condition in P. marginatus ( Stimpson, 1858) . In P. granulatus , however, the granules on the dorsal carapace surface are more distinct, more raised and more widespread, and there is dense short pile-like pubescence between the raised regions ( Fig. 2A, B View FIGURE 2 ) (versus the granules are lower, and the carapace lacks the pile-like pubescence but instead has numerous longer setae on P. marginatus ; Fig. 5F View FIGURE 5 ). In addition, the frontal margin is lined with prominent rounded granules ( Fig. 2C View FIGURE 2 ) (versus with low granules in P. marginatus ; Fig. 5D View FIGURE 5 ); the outer surface of the third maxilliped has short pubescence ( Fig. 2C View FIGURE 2 ) (versus surface is densely setose in P. marginatus ; Fig. 5C View FIGURE 5 ); and the setae on the outer surfaces of the cheliped are low and visible only between the granules ( Fig. 2G View FIGURE 2 ) (versus setae are overall distinctly denser and longer in P. marginatus ; Fig. 5F View FIGURE 5 ).

ZMH	Zoologisches Museum Hamburg

Copyright notice

No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.

Taxonomy

Kingdom	Animalia
Phylum	Arthropoda
Class	Malacostraca
Order	Decapoda
InfraOrder	Brachyura
SuperFamily	Pilumnoidea
Family	Pilumnidae
SubFamily	Pilumninae
Genus	Pilumnopeus