Revision of the intertidal and semiterrestrial crab genera Chiromantes Gistel, 1848, and Pseudosesarma Serène & Soh, 1970 (Crustacea: Brachyura: Sesarmidae), using morphology and molecular phylogenetics, with the establishment of nine new genera and two new species
Author
Schubart, Christoph D.
Zoology & Evolution, University of Regensburg, 93040 Regensburg, Germany
christoph.schubart@ur.de
Author
Ng, Peter K. L.
Lee Kong Chian Natural History Museum, Faculty of Science, National University of Singapore, 2 Conservatory Drive, Singapore 117377, Republic of Singapore
peterng@nus.edu.sg
text
Raffles Bulletin of Zoology
2020
2020-12-23
68
891
994
journal article
55667
10.26107/RBZ-2020-0097
6cb155ce-8b9f-48ce-8e6c-b0dc00f8b1cc
2345-7600
5351295
815E4670-B063-4FD8-B31E-3AD89B3A7942
Cristarma ortmanni
(
Crosnier, 1965
)
(
Figs. 13F
,
14F
,
15E, F
,
18D
,
20I–K
,
43H
)
Sesarma quadrata
–
Hilgendorf, 1869: 90
, pl. 3 fig. 3c, pl. 4 fig. 3 [not
Cancer quadratus
Fabricius, 1798
].
Sesarma erythrodactyla
var.
africana
–
Ortmann, 1894: 56
[not
Sesarma africana
H. Milne Edwards, 1837
].
Sesarma ortmanni
Crosnier, 1965: 51
, figs. 70, 71.
Sesarma
(
Holometopus
)
ortmanni
–
Serène, 1968: 107
.
Holometopus ortmanni
–
Hartnoll, 1975: 308
, 311, 316.
Chiromantes ortmanni
–
Naderloo & Schubart, 2009: 67
.
“
Chiromantes
”
ortmanni
–
Ng et al., 2008a: 220
;
Emmerson, 2016: 240
, unnumbered colour fig.
Material examined
.
Lectotype
(here designated): male (10.7 ×
8.2 mm
) (
MNHN
B16741a),
Nosy Be
,
Tuléar
,
Madagascar
, coll.
A. Crosnier
, 1960s
.
Paralectotypes
:
1 male
(8.6 ×
6.7 mm
),
2 females
(10.9 ×
8.6 mm
, 12.7 ×
9.8 mm
) (
MNHN
B16741b), same data as lectotype.
KENYA
–
2 males
(19.4 ×
14.4 mm
, 15.1 ×
11.9 mm
),
2 females
(13.1 ×
10.2 mm
, 10.9 ×
8.6 mm
) (
ZRC 2000.1783
),
Gazi
, coll.
M. Vannini
,
November 1991
.
MOZAMBIQUE
–
1 male
(20.0 ×
15.5 mm
) (
ZRC
1968.1.22.1),
Inhaca Island
, coll.
MacNae
,
April 1967
.
Fig. 21. A–G,
Trapezarma angolense
, neotype male (39.3 × 32.7 mm) (SMF-ZMG 635), Benguella, Angola; H–L,
Platychirarma buettikoferi
, 1 male (10.7 × 8.8 mm) (SMF 25980), West Nimbe Cameroon. A, H, male pleon; B, I, left G1 (ventral view, denuded); C, left G1 (dorso-lateral view) (denuded); D, J, left G1 (dorsal view, denuded); E, K, left distal part of G1 (ventral view, denuded); G, L, left distal part of G1 (dorsal view, denuded); F, left distal part of G1 (dorso-lateral view) (denuded). Scales: A = 5.0 mm; B–D, H = 2.0 mm; E–G, I, J = 1.0 mm; K, L = 0.5 mm.
Diagnosis
. Carapace proportionately broader, transversely rectangular; lateral margin almost straight; dorsal margin of male cheliped dactylus with about 12 slightly asymmetrical tubercles which get progressively smaller distally; male pleon proportionately broader, shorter.
Colour
. According to
Crosnier (1965: 53)
, the carapace is green with the ambulatory legs yellowish.
Emmerson (2016: 240
, unnumbered colour fig.) depicts a specimen with bright red chelae and a beige transverse faceband on the carapace.
Remarks
. Some nomenclatural notes on this species are necessary. In describing
Sesarma
(
Holometopus
)
ortmanni
,
Crosnier (1965)
suggested that it may be the same as
Sesarma erythrodactyla
var.
africana
Ortmann, 1894
.
Crosnier (1965: 53)
commented that “le type de
Sesarma erythrodactyla
var.
africana
ne se trouve pas au Muséum de Strasbourg où est déposée la collection d’ORTMANN. La description de cette espèce est, d’autre part, assez sommaire. Il est donc impossible de savoir avec certitude si l’espèce que nous considérons ci-dessus est la même que celle décrite par ORTMANN. Nous pensons toutefois qu’il y a de fortes chances qu’il en soit ainsi et c’est pour cela que nous dédions notre espèce à ORTMANN. L’examen de spécimens des espèces de
Sesarma
existant à
Dar es Salam
(localité du
type
d’ORTMANN) permettrait vraisemblablement d’éclaircir le problème.
Sesarma erythrodactyla
Hess
appartient au sous-genre
Parasesarma
; l’espèce que nous appelons
S. ortmanni
au sous-genre
Holometopus
. Si donc
S. ortmanni
et
S. erythrodactyla
var.
africana
sont identiques, l’espèce d’ORTMANN ne doit pas être considérée comme une variété de
S. erythrodactyla
mais comme une espèce distincte. Il n’est pas possible de l’appeler
S. africana
, ce nom ayant déjà été donné par H. MILNE EDWARDS à une espèce de
Sesarma
de la côte oust de l’Afrique.
Sesarma ortmanni
est donc soit une espèce nouvelle, soit simplement, si son identité avec l’espèce d’ORTMANN peut être clairement établie, une nouvelle désignation de
S. erythrodactyla
var.
africana
”.
Sesarma erythrodactyla
var.
africana
Ortmann, 1894
, is clearly a junior primary homonym of
Sesarma africana
H. Milne Edwards, 1837
, and according to article 57.2 of the current zoological code (
ICZN, 1999
), the name needs to be replaced. Although Article 23.9.5 allows for a junior primary homonym to be retained, it states that “When an author discovers that a species-group name in use is a junior primary homonym [Art. 53.3] of another species-group name also in use, but the names apply to taxa not considered congeneric after 1899, the author must not automatically replace the junior homonym; the case should be referred to the Commission for a ruling under the plenary power and meanwhile prevailing usage of both names is to be maintained [Art. 82]”. The requirements of Article 23.9.5 are not fulfilled because even after 1899, H. Milne Edwards’ and Ortmann’s names were used together in the same genus by some authors. For example,
Tesch (1917)
uses both “
Sesarma
(
Chiromantes
)
africana
H. Milne Edwards
” (p. 129) and “
Sesarma
(
Parasesarma
)
erythrodactyla africana
Ortmann
” (p. 140); and although he has them in different subgenera and species-groups, the fact remains that both taxa were placed in “
Sesarma
” and the zoological code (Article 57.1) treats species and subspecies as species-group names and therefore of equal status. As such,
Sesarma erythrodactyla
var.
africana
Ortmann, 1894
, is not an available name. This situation remains even if
Sesarma africana
H. Milne Edwards, 1837
, is currently regarded as a junior subjective synonym of
Perisesarma huzardi
(
Desmarest, 1825
)
. As discussed by
Crosnier (1965)
, it is likely that
Sesarma erythrodactyla
var.
africana
Ortmann, 1894
, is conspecific with
Sesarma
(
Holometopus
)
ortmanni
Crosnier, 1965
. In the event they are not, then
Ortmann’s (1894)
name must be replaced if there is no senior synonym.
Fig. 22. Overall habitus,
Pseudosesarma
species. A
,
P. edwardsii
,
lectotype
male (17.5 ×
16.1 mm
) (RMNH-D17a), Mergui Archipelago; B,
P. edwardsii
, male (13.4 ×
11.9 mm
) (ZRC 1965.8.2.81), Pulau Pawai,
Singapore
; C,
P. edwardsii
, male (12.9 ×
11.8 mm
) (ZRC 1971.9.24.9),
Singapore
; D,
P. crassimanum
, male (15.9 ×
14.5 mm
) (RMNH-D23313),
Singapore
; E,
P. anteactum
,
holotype
male (16.7 ×
14.7 mm
) (ZRC 2016.0602),
Sri Lanka
; F,
P. glabrum
,
holotype
male (13.8 × 12.0 mm) (CUSAT 2016-1),
Kerala
,
India
; G,
P. brehieri
,
holotype
male (17.4 ×
15.7 mm
) (ZRC 2016.0593),
Myanmar
; H,
P. boulengeri
,
lectotype
male (26.9 ×
23.5 mm
) (NHM 1919.11.14.1),
Basra
,
Iraq
.
Fig. 23. A, E,
Contusarma bocourti
, lectotype male (24.0 × 27.2 mm) (MNHN D-10965), Bangkok, Thailand; B, F,
C. bocourti
, male (25.3 × 23.3 mm) (ZRC 2000.0952), Bangkok, Thailand; C,
C. bocourti
, female (21.1 × 19.0 mm) (ZRC 2019.1114), Bangkok, Thailand; D, H,
C. cheirogonum
, neotype male (24.5 × 21.5 mm) (ZRC 1995.225), Bako National Park, Sarawak; G,
C. cheirogonum
, male (23.0 × 20.7 mm) (ZRC 2000.2018), Pulau Ubin, Singapore. A–D, overall habitus; E–H, anterior half of carapace.
In naming this species,
Crosnier (1965: 51)
stated he had
two males
and
two females
but did not specify a
holotype
. As such, all his specimens are
syntypes
. The largest male (10.7 ×
8.2 mm
) (MNHN B16741a) is here designated the
lectotype
of
Sesarma ortmanni
Crosnier, 1965
.
Biology
.
Hartnoll (1975: 316)
records this species as occurring in terrestrial vegetation above the supralittoral zone all the way down to the sand flats and
Avicennia
mangrove zone.
Distribution
. Along the eastern and southern coasts of Africa (
Crosnier, 1965
;
Hartnoll, 1975
;
Emmerson, 2016
).
Emmerson (2016: 241–243)
provides a detailed summary of the known ecology and biology of the species.