New insights into the identities of the elasmobranch fauna of Sri Lanka
Author
Fernando, Daniel
Author
Bown, Rosalind M. K.
Author
Tanna, Akshay
Author
Gobiraj, Ramajeyam
Author
Ralicki, Hannah
Author
Jockusch, Elizabeth L.
Author
Ebert, David A.
Author
Jensen, Kirsten
Author
Caira, Janine N.
text
Zootaxa
2019
2019-04-12
4585
2
201
238
journal article
27326
10.11646/zootaxa.4585.2.1
86f58653-808d-45ee-bba8-2706327e1afd
1175-5326
2637236
8519C595-0A62-4710-8D38-B200951D7B19
Centrophorus
cf.
atromarginatus
(
Figs. 5E
,
18
A–C)
Six specimens (SL-85, SL-86, SL-87, SL-88, SL-89, and SL-95) of the short-snout group of
Centrophorus
Müller & Henle
species were examined from the deep-sea longline landing site in Mutur in the Eastern Province. Although definitive identification of many species of
Centrophorus
remains problematic (e.g., see Verissimio
et al.
2014;
White
et al.
2017
), these specimens do not conform to the description of any of the 12 valid species in the genus. A female specimen of this species has been deposited in the BRT Ichthyology Collection (SL-87; BRT-I 0021). In the tree resulting from the Neighbor-Joining analysis, these six specimens grouped in a tight cluster, differing from one another by 0–4 bp in NADH2 sequence. We have preliminary identified these specimens as
Centrophorus
cf.
atromarginatus
. The specimens most closely resemble
Centrophorus atromarginatus
Garman
but appear to differ from this species in that the black coloration on the dorsal fins is not restricted to the posterior margins but covers the dorsal half of both fins. In addition, the pectoral fins lack black posterior margins, as does the upper lobe of the caudal fin. Examination of the
holotype
and voucher specimens of
C. atromarginatus
from throughout its current known distribution from
Japan
to the Gulf of Aden reveals some morphological variation, suggesting it may constitute a species complex (DAE, unpubl data). Unfortunately, NADH2 data for a confirmed reference specimen of
C. atromarginatus
were unavailable. Further comparison of regional specimens and generation of NADH2 data for specimens of
C. atromarginatus
from its type locality in
Japan
(see
Eschmeyer
et al.
2018
) would be useful to confirm this lack of conspecificity. We have employed this name in recognition of the fact that these specimens may represent additional novelty in the genus.
Three species of
Centrophorus
have been reported from
Sri Lanka
:
Centrophorus moluccensis
Bleeker
(e.g.,
Joseph, 1999
; tentatively
Ebert, 2013
;
De Silva, 2015
),
Centrophorus squamosus
(Bonnaterre)
(e.g.,
Morón
et al
. 1998
;
Weerakkody & Fernando 2000
;
De Silva 2006
,
2015
), and
Centrophorus uyato
Rafinesque
(e.g., tentatively
Morón
et al
. 1998
;
Joseph, 1999
). This is one of the candidates for the species referred to in one or more of these reports, but in the absence of detailed images, this is difficult to assess.