Machaerus atlanticus ( Miers, 1881 )

CASTRO, PETER & NG, PETER K. L., 2010, Revision of the family Euryplacidae Stimpson, 1871 (Crustacea: Decapoda: Brachyura: Goneplacoidea), Zootaxa 2375 (1), pp. 1-130 : 77-78

publication ID	https://doi.org/10.11646/zootaxa.2375.1.1
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scientific name	Machaerus atlanticus ( Miers, 1881 )
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Machaerus atlanticus ( Miers, 1881) View in CoL

( Figs. 29A–D View FIGURE 29 ; 32A, B View FIGURE 32 )

Pilumnoplax sulcatifrons var. atlantica Miers, 1881: 259 View in CoL , 375 [in list; Senegal]; 1886: 226 [in list].

Pilumnoplax atlantica View in CoL — Monod 1956: 340 [in key], 341, figs. 442—449 [ Senegal, Guinea, Sierra Leone]. — Forest & Guinot 1966: 85 [ Guinea, Ghana, Nigeria]. — Crosnier 1969: 531 [Congo-RC]. — Guinot 1969b: 517, 518 [discussion] [ Senegal]; 1969c: 688; 1971: 1081 [in list]. — d’Udekem d’Acoz 1999: 242 [in list] [references].

“ Pilumnoplax View in CoL ” atlantica View in CoL — Guinot 1969b: 507, 508 [discussion], figs. 36, 53.

[ Pilumnoplax View in CoL ] atlantica View in CoL — Guinot 1971: 1081 [in list].

Machaerus atlanticus View in CoL — Manning & Holthuis 1981: 162 [references] [ Ivory Coast, Ghana]. — Ng et al. 2008: 78 [in list].

not Pilumnoplax atlantica View in CoL — Balss 1922b: 76 [ Liberia, Ivory Coast, Equatorial Guinea]. — Monod 1933: 533, fig. 19A, 20, 21E [ Mauritania]. — Capart 1951: 166, fig. 63 [ Gabon, Cabinda, Congo-RC]. [= Machaerus oxyacanthus ( Monod, 1956) View in CoL ]

Type material. Unknown status (not MNHN) .

Type locality. Senegal, Gorée I.

Material examined. Mauritania. M. Monod coll., 1923, id. as Pilumnoplax atlantica by M. Monod: 1 male ( MNHN-B10237 ) .

Senegal. Gorée I., Marche-Marchand coll., 09.01.1951: 1 ovigerous female, 6.0 mm × 8.2 mm (MNHN- B10239). – Joal, 10–11 m, 20.02.1953: 1 male 8.2 mm × 10.9 mm ( MNHN-B10240 ); 4 m, 19.02.1953: 2 males, 6.5 mm × 8.9 mm, 6.5 mm × 9.0 mm ( MNHN-B 10238 ) .

Guinea. Calypso , stn. 7, 18 m, 17.05.1956: 2 males, 2 pre-adult females ( MNHN-B10233 ) .

Diagnosis. Anterolateral teeth, outer orbital teeth about same size, shape, second tooth only slightly longer than the first, third ( Fig. 29A, B View FIGURE 29 ).

Remarks. Machaerus atlanticus appears to be sympatric with its only known congener, M. oxyacanthus . Both species can be easily differentiated from each other by the morphology of the anterolateral teeth. All three anterolateral teeth and the outer orbital teeth are about the same size and shape in M. atlanticus , with the second tooth only slightly longer than the first and third ( Fig. 29A, B View FIGURE 29 ). The anterolateral teeth of M. oxyacanthus are acute, different from the triangular outer orbital teeth, and the second anterolateral teeth much longer and more elevated than the first ( Fig. 30A, B View FIGURE 30 ). Monod (1956: 345) provided some colour notes of a freshly preserved specimen, and there are some apparent differences between its colour pattern and that of M. atlanticus (see Manning & Holthuis 1981: 163).

Distribution. Atlantic coast of Africa from Senegal to Congo (RC). Depth: 4–100 m ( Manning & Holthuis 1981).

References

Balss, H. (1922 b) Decapoda Brachyura (Oxyrhyncha und Brachyrhyncha) und geographische Ubersicht uber Crustacea Decapoda, Crustacea VII. In: W. Michaelsen, Beitrage zur Kenntniss der Meeresfauna Westafrikas, 3 (3), 70 - 110, Hamburg.

Capart, A. (1951) Crustaces Decapodes, Brachyoures. In: Expedition Oceanographique Belge dans les Eaux Cotieres Africaines de l'Atlantique Sud (1948 - 1949), 3 (1), 11 - 205, pls. 1 - 3.

Crosnier, A. (1969) Sur quelques Crustaces Decapodes ouest-africains. Description de Pinnotheres leloeuffi et Pasiphaea ecarina spp. nov. Bulletin du Museum national d'Histoire naturelle (Paris), ser. 2, 41 (2), 529 - 543.

Udekem d'Acoz, C. d' (1999) Inventaire et distribution des crustaces decapodes de l'Atlantique nord-oriental, de la Mediterranee et des eaux continentales adjacentes au nord de 25 ° N. Patrimoines Naturelles, Museum national d'Histoire naturelle, Paris, 40, i - x, 1 - 383

Forest, J. & Guinot, D. (1966) Crustaces Decapodes: Brachyoures. In: Campagne de la Calypso dans le golfe de Guinee et aux iles Principe, Sao Tome et Annobon (1956), no. 16. Annales de l'Institut Oceanographique, n. s., 44, 23 - 124.

Guinot, D. (1969 b) Recherches preliminaries sur les groupements naturels chez les Crustaces Decapodes Brachyoures, VII. Les Goneplacidae (suite). Bulletin du Museum national d'Histoire naturelle (Paris), ser. 2, 41 (2), 507 - 528, pl. 2.

Guinot, D. (1971) Recherches preliminaries sur les groupements naturels chez les Crustaces Decapodes Brachyoures, VIII. Synthese et bibliographie. Bulletin du Museum national d'Histoire naturelle (Paris), ser. 2, 42 (5) [1970], 1063 - 1090.

Manning, R. B. & Holthuis, L. B. (1981) West African Brachyuran crabs (Crustacea: Decapoda). Smithsonian Contributions to Zoology no. 306, xii + 379 pp.

Miers, E. J. (1881) On a collection of Crustacea made by Baron Hermann-Maltzam [sic] at Goree Island, Senegambia. Annals and Magazine of Natural History, ser. 5, 8, 204 - 220, 259 - 281, 364 - 377, pls. 13 - 16.

Monod, T. (1933) Sur quelques Crustaces de l'Afrique Occidentale (liste des Decapodes mauritaniens et des Xanthides oust-africains). Bulletin du Comite d'Etudes Historiques et Scientifiques de l'Afrique Occidental Francaise 15 (2 - 3) [1932], 456 - 548.

Monod, T. (1956) Hippidea et Brachyura ouest-africains. Memoires de l'Institut Francais d'Afrique Noire, no. 45, 1 - 674.

Ng, P. K. L., Guinot, D. & Davie, P. (2008) An annotated checklist of extant brachyuran crabs of the world. Systema Brachyurorum, Part I. Raffles Bulletin of Zoology, Supplement 17, 1 - 286.

Figures

FIGURE 29. Machaerus atlanticus (Miers, 1881); A, B, male (6.5 mm × 8.9 mm) (MNHN-B 10238), Senegal, Joal; C, D, ovigerous female (6.0 mm × 8.2 mm) (MNHN-B10239), Senegal. Gorée I. A, C, overall views; B, anterior portion of male thoracic sternum and abdomen; D, female thoracic sternum and vulvae. Abbreviations: s4–s6 = thoracic sternites 4 to 6, respectively; v = vulva.

FIGURE 30. Machaerus oxyacanthus (Monod, 1956); male (19.0 mm × 30.3 mm) (MNHN-B10242), Sierra Leone. A, overall view; B, frontal view showing orbits and antennae; C, third maxillipeds; D, outer surface of left chela; E, male thoracic sternum and abdomen; F, male sterno-abdominal cavity, G1, and penis; G, posterior portion of male thoracic sternum and abdomen. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; G1 = first male pleopod; G2 = second male pleopod; g = male gonopore; p = penis; s4–s8 = thoracic sternites 4 to 8, respectively.

FIGURE 32. A, B, Machaerus atlanticus (Miers, 1881) (after Guinot 1969b: figs. 36, 53, as “Pilumnoplax” atlantica); C–F, Machaerus oxyacanthus (Monod, 1956) (after Guinot 1969b: figs. 38, 54a, 54b, 55, as “Pilumnoplax” oxyacantha); G–K, Nancyplax vossi Lemaitre, García-Gómez, von Sternberg & Campos, 2001 (after Lemaitre et al. 2001: figs. 5b–e). A, C, posterior portion of male thoracic sternum, abdomen, and gonopore; B, D, E, H, I, G1; F, J, K, G2. Abbreviation: a1–a3 = male abdominal somites 1, 2, 3, respectively; g = male gonopore.

Abbreviations

MNHN	Museum National d'Histoire Naturelle

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
Family	Euryplacidae
Genus	Machaerus