Osteobrama bhimensis (Cypriniformes: Cyprinidae): a junior synonym of O. vigorsii
Shrikant
S. Jadhav 1, Mandar Paingankar 2 & Neelesh Dahanukar3
1 Zoological
Survey of India, Western Regional Centre, Vidyanagar, Akurdi, Pune, Maharashtra
411044, India
2 Prerana
Heights, Flat No. B13, Balaji Nagar, Dhankawadi, Pune, Maharashtra 411043,
India
3 Indian
Institute of Science Education and Research, Sai
Trinity, Garware Circle, Pune, Maharashtra 411021, India
Email: 1 shrikantj123@yahoo.com, 2 mandarpaingankar@gmail.com, 3 n.dahanukar@iiserpune.ac.in(corresponding author)
Date of
publication (online): 26 September 2011
Date of
publication (print): 26 September 2011
ISSN
0974-7907 (online) | 0974-7893 (print)
Editor: Anonymity
requested
Manuscript details:
Ms # o2841
Received 22 June 2011
Final received 17 July 2011
Finally accepted 15 August 2011
Citation: Jadhav,
S.S., M. Paingankar & N. Dahanukar (2011). Osteobrama
bhimensis (Cypriniformes:Cyprinidae): a junior synonym of O.
vigorsii. Journal of Threatened Taxa 3(9): 2078–2084.
Copyright: © Shrikant
S. Jadhav, Mandar Paingankar & Neelesh Dahanukar 2011. Creative
Commons Attribution 3.0 Unported License. JoTT allows unrestricted use
of this article in any medium for non-profit purposes, reproduction and
distribution by providing adequate credit to the authors and the source of
publication.
Author Detail: Shrikant S. Jadhav is Scientist A at the Zoological Survey
of India, Western Regional Centre, Pune. He works on
taxonomy and distribution of freshwater fishes and has published several papers
in this area. Mandar Paingankar is a molecular
biologist and works on vector biology with an emphasis on host parasite
interactions. He works on animal ecology as a hobby. Neelesh Dahanukarworks in ecology and evolution with an emphasis on mathematical and statistical
analysis. He is also interested in taxonomy, distribution patterns and
molecular phylogeny of freshwater fishes.
Author Contribution: SSJ and ND
put forth the concept. SSJ, MP and ND collected the data, analyzed the data and
wrote the paper.
Acknowledgements: We are
thankful to Dr. R.M. Sharma, Scientist-D and Officer-in-charge, Zoological
Survey of India, Western Regional Centre, Akurdi, Pune, and Dr. G.M. Yazdani
for encouragement and support. We are grateful to Varsha Mysker for providing
two specimens of Osteobrama vigorsii from Bhima
River at Kollakur, Karnataka. We are also grateful to two anonymous referees
for critical comments on an earlier draft of our manuscript.
Abstract: Osteobrama
bhimensis (Singh & Yazdani) was described
from the Ujani wetland on Bhima River in Maharashtra, India, about 100 km
downstream of the type locality of O. vigorsii (Sykes).
Based on examination of the type material of O. bhimensis and comparison
with O. vigorsii collected
from different localities in the Krishna and Godavari River systems, we show
that O. bhimensis is
conspecific with O. vigorsii.
Keywords:Conspecific, junior synonym, Osteobrama bhimensis, Rohtee
vigorsii.
For figures, images, tables -- click
here
INTRODUCTION
Sykes (1839) described Rohtee vigorsii (now Osteobrama) from the Bhima River at Pairgaon
(approx. 18.5060N & 74.7040E). Although the types of this species are
missing (Eschmeyer & Fricke 2011), Sykes (1841) provided a clear
illustration of the species and gave an adequate description for purposes of
identification. The species is
widely distributed in the Krishna, Godavari and Mahanadi river systems of
peninsular India and is common throughout its range (Dahanukar 2011). Singh & Yazdani (1992) described Osteobrama bhimensis from the Ujani Wetland
on Bhima River, about 100km downstream of the type localityof O. vigorsii. Osteobrama bhimensis has since been
considered a valid species by most authors (e.g., Menon 1999; Jayaram
2010). Even though Singh &
Yazdani (1992) considered O. bhimensis to
be closely related to O. cotio,
owing to the lack of barbels, their figure of O. bhimensis resembles O. vigorsii more than it does O. cotio. Singh & Yazdani (1992) did, however,
mention the similarity between O. bhimensisand O. vigorsiiand sought to distinguish the two species through a number of characters
(discussed below).
Recently we had an opportunity to study
all the type material, comprising the holotype and five paratypes, of O. bhimensis currently in the collection of the
Zoological Survey of India, Western Regional Centre, Pune. We compared the type material of O. bhimensis with specimens of O. vigorsii from the Krishna and Godavari river
systems. Our study suggests that O. bhimensisand O. vigorsiiare conspecific.
METHODS
Data
collection
The type material of Osteobrama bhimensis, comprising of the
holotype and five paratypes, was available in the fish collection of the
Zoological Survey of India, Western Regional Centre, Pune(ZSI Pune). Specimens of O. vigorsii and O. cotio peninsularis were available in the
Wildlife Information Liaison Development, Coimbatore (WILD) and ZSI Pune. Morphometric and meristic data were
recorded following Jayaram (2010). Measurements were taken point to point using
dial calipers to the nearest hundredth of an inch and then converted to
millimetres. Subunits of the body
are presented as a percent of standard length (SL) and subunits of the head are
presented as a percent of head length (HL). All pored scales were counted for reporting the lateral
lines scales. We dissected three specimens of O. vigorsii (P/2671, 110mm SL; P/2672, 105mm SL and
P/2673, 128mm SL) to resolve the structure of the urohyal bone.
Material
examined
Osteobrama bhimensis:
Holotype, 06.ix.1989, Bhima River, Saha Village (approx. 18.1330N &
75.0930E), Indapur Taluka, Pune District, Maharashtra, coll. D.F.
Singh (ZSI Pune P/1235). Paratypes, 5 ex., collection data same as holotype (ZSI Pune P/1236).
Osteobrama vigorsii: 1
ex., WILD-11-PIS-017, Mula-Mutha River at Yerawada
(18.5420N & 73.8770E), collected on 14.i.2011 by N.
Dahanukar & M. Paingankar; 1 ex., ZSI Pune P/2670, Bhima River at
Koregaon-Bhima (18.6470N & 74.0540E), collected on
25.v.2011 by N. Dahanukar & M. Paingankar; 1 ex., ZSI Pune P/2672,
Mula-Mutha River at Yerawada (18.5420N & 73.8770E),
collected on 07.i.2011 by N. Dahanukar & M. Paingankar; 1 ex., ZSI Pune
P/2673, Krishna River at Wai (17.9560N & 73.8790E),
collected in March 2011 by N. Dahanukar & M. Paingankar; 1 ex., ZSI Pune
P/2671, Nira River at Bhor (18.1530N, 73.8430E),
collected in December 2009 by N. Dahanukar & M. Paingankar; 1 ex., ZSI Pune
P/2674, Wasumbre tank (approx. 17.2980N, 74.5790E) in
Sangli District, collected on 16.vi.1979 by A.S. Mahabal; 1 ex., ZSI Pune
P/2676, Mutha River at Warje (18.4810N, 73.8160E),
collected on 24 February 1999 by N. Dahanukar; 1 ex., ZSI Pune P/2675, Mula
River at Aundh (18.5680N & 73.8110E), collected on
02.vi.1999 by N. Dahanukar; 2 ex., unregistered, Bhima River at Kollakur
(17.0860N & 76.7640E), collected on 10.v.2011 by
Varsha Mysker; 3 ex., ZSI Pune P/2105, Godavari River at Kaigaon (approx.
19.6240N, 75.0260E) in Gangapur Taluka, Aurangabad,
collected on 13.x.1999 by P.P. Kulkarni.
Osteobrama cotio peninsularis: 1
ex., WILD-11-PIS-015, Mula-Mutha River at Yerawada
(18.5420N & 73.8770E), collected on 07.i.2011 by N.
Dahanukar & M. Paingankar; 1 ex., ZSI Pune P/2595, Indrayani River at
Markal (18.6730N & 73.9840E), collected during 2009–2010
by N. Dahanukar & M. Paingankar; 1 ex., ZSI Pune P/2443, Nira River at Bhor
(18.1530N & 73.8430E), collected on 01.i.2011 by N.
Dahanukar & M. Paingankar; 1 ex., ZSI Pune P/2684, Mula River at Paud
(18.5290N & 73.6110E), collected on 08.vi.2011 by N.
Dahanukar & M. Paingankar; 3 ex., ZSI Pune P/2685, Mula-Mutha River at
Yerawada (18.5430N & 73.8790E), collected on
16.vi.2011 by N. Dahanukar & M. Paingankar.
RESULTS
AND DISCUSSION
One of the most important characters that
Singh & Yazdani (1992) used for diagnosing Osteobrama bhimensis was the absence of barbels. Our study of the type material of O. bhimensis revealed that the holotype and all the
paratypes of O. bhimensis do
in fact possess a pair of rudimentary maxillary barbels (Image 1), a character
state also present in O. vigorsii. Indeed, if the character state ‘barbels
present’ were applied to specimens of O. bhimensis using Singh & Yazdani’s (1992) own
key, the species keys out as O. vigorsii.
Singh & Yazdani (1992) suggested that O. bhimensis is related to O. cotio and compared it with two subspecies of O. cotio, namely O. cotio cotio and O. cotio cunma. Even though these authors did not
explicitly mention why they consider O. bhimensis to be affined to O. cotio, it appears they considered the absence
of barbels in O. bhimensis to
be synapomorphic in the O. bhimensis-O. cotio group. Our data, however, does not suggest a
closer relationship between O. bhimensis andO. cotio than
that between the former species and O. vigorsii, for two reasons. First, the holotype and all the
paratypes of O. bhimensis do
possess rudimentary barbels (Image 1). Second, the morphometric and meristic data of O. bhimensis do not coincide substantially with O. cotio, an observation that was also made by
Singh & Yazdani (1992). Interestingly, Singh & Yazdani (1992) did not compare O. bhimensis with O. cotio peninsularis described by Silas
(1952) from Poona [= Pune], which is close to the type locality of O. bhimensis. Our comparison suggests that O. bhimensis differs from O. cotio peninsularis in a number of
characters including ii22–ii24 (vs. ii27–ii32 in O. c. peninsularis) anal fin rays, 26-30
(vs. 17–18) predorsal scales, 72–79 (vs. 55–56) lateral-line
scales and head length 26.0–28.3 % SL (vs. 22.3–24.0 % SL).
The type material of O. bhimensis and the figure given in Singh &
Yazdani (1992, fig. 1), however, is consistent with Sykes’ (1842) description
and figure of O. vigorsii, a
species very widely distributed across the Krishna and Godavari river systems
of the north-central part of the peninsular India. A comparison of the morphometric data of the type series of O. bhimensis with the material of O. vigorsii referred to herein, from a number of
locations across the Krishna River and Godavari basins (Fig. 1), suggests that
the morphometric and meristic data of O. bhimensis substantially overlap with those of O. vigorsii (Table 1, Appendix A, B). Further,
comparison of images of the types of O. bhimensis with those of O. vigorsii from a variety of sources, and the
illustration of Sykes (1841) iteself, shows a remarkable resemblance (Image 2).
Although Singh & Yazdani (1992) were
aware of the resemblance between O. bhimensisand O. vigorsii,
they separated the former from the latter based on the absence of barbels (vs.
presence), 13–17 transverse scale rows between lateral line and pelvic
fin base (vs. 11–11½ ), the possession of
24–32 predorsal scales (vs. 33–37), and the structure of urohyal.
As already mentioned, the entire type series of O. bhimensis possesses rudimentary maxillary barbels,
a character state shared with O. vigorsii.
Although Singh & Yazdani (1992, Table 2) mention the number of transverse
scale rows between lateral line and pelvic fin base as 13-15, we count 11 or 11½
(Table 1), which is the same range also for O. vigorsii (Hora & Misra 1940; Singh &
Yazdani 1992; see also Table 1). The predorsal scales of O. bhimensisand O. vigorsiialso have overlapping ranges (Table 1).
An additional difference that Singh &
Yazdani (1992) used to differentiate O. bhimensis from O. vigorsii was the shape of the urohyal. This is a single median triradiate bone
with the anterior tip connected to the ventral hypohyals, the antero-dorsal
part of which is connected to the first basibranchial and the posterior part of
which is connected to the pectoral girdle by means of muscles (Johal et al.
2000). The shape of the urohyal of O. vigorsii(Image 3) matches that of O. bhimensis as
illustrated in fig. 2 of Singh & Yazdani (1992). Singh & Yazdani (1992) suggested that the urohyal of O. vigorsii exhibits a radial process on the vertical
plate, which is absent in O. bhimensis. However, in the three specimens of O. vigorsii we dissected, there is no such radial
process (note that in Image 3a the thickened area on the lower surface is
merely an undulation, not a process). Further, Singh & Yazdani (1992) mention that the dorsal spread ends
in equal wings in O. bhimensis,
while it ends in unequal wings in O. vigorsii.
Our specimens of O. vigorsiishow the dorsal spread to end in two equal wings (Image 3b). Therefore, the difference between the
urohyals of O. bhimensisand O. vigorsiimentioned by Singh & Yazdani (1992) do not, in fact, exist. We did not dissect any of the type
specimens of O. bhimensis. However, it is important to note that
even though Singh & Yazdani (1992) mentioned that they studied the urohyal
bone of O. bhimensisand O. vigorsii,
they omitted to mention which specimens were used for their study. It is clear that none of the types of O. bhimensis have been dissected or cleared and
stained.
The present study shows, therefore, that
all the differences stated by Singh & Yazdani (1992) as distinguishing O. bhimensis from O. vigorsii do not in fact exist: the two nominal
species are in fact conspecific and, O. vigorsii being the senior one, is valid, while O. bhimensis must now be placed in its synonymy.
Dahanukar (2010) assessed the IUCN
conservation status of Osteobrama
bhimensis as Endangered under criteria B1ab(iii)+2ab(iii) (IUCN 2001) owing to the fact that the
species is known only from its type locality in the Ujani wetland, with an
Extent of Occurrence of 260km2 and threats to the habitat and the
species due to increasing urbanization, agricultural pollution and invasive
exotic fishes. Dahanukar (2010)
also noted the need to validate the taxonomy of this nominal species because of
its remarkable similarity to O. vigorsii.
In the current study we have established that O. bhimensis is not a valid species but a junior
subjective synonym of O. vigorsii.
REFERENCES
Dahanukar, N. (2010). Osteobrama bhimensis. In: IUCN 2011. IUCN Red
List of Threatened Species. Version 2011.1. <www.iucnredlist.org>.
Downloaded on 18 June 2011.
Dahanukar,
N. (2011). Osteobrama vigorsii. In: IUCN 2011. IUCN
Red List of Threatened Species. Version 2011.1. <www.iucnredlist.org>.
Downloaded on 18 June 2011.
Eschmeyer,
W.N. & R. Fricke (eds.) (2011). Catalog of Fishes electronic
version. http://research.calacademy.org/ichthyology/catalog/fishcatmain.asp.
Online version dated 5 May 2011. Downloaded on 20 June 2011.
Hora,
S.L. & K.S. Misra (1940). Notes on fishes in the Indian museum. XL. On
fishes of the genus RohteeSykes. Records of the Indian Museum42(1): 155–172.
IUCN
(2001). IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN,
Gland, Switzerland and Cambridge, UK, ii+30pp.
Jayaram,
K.C. (2010). The Freshwater Fishes of The Indian Region.Second Edition. Narendra
Publishing House, Delhi, 616pp.
Johal,
M.S., H.R. Esmaeili & K.K. Tandon (2000). Reliability of urohyal bone of silver carp, Hypophthalmichthys
molitrix (Val. 1844) for age determination. Current Science 79(1): 27–28.
Menon,
A.G.K. (1999). Check list - fresh water fishes of India. Occasional Paper No. 175. Records of the
Zoological Survey of India, Kolkata. 366pp.
Silas,
E.G. (1952). Further studies regarding Hora’s Satpura
hypothesis. Proceedings of the National Institute of
Sciences of India 18(5): 423-448.
Singh,
D.F. & G.M. Yazdani (1992). Osteobrama bhimensis, a new cyprinid fish from Bhima River,
Pune District, Maharahtra. Journal of the Bombay Natural History Society89(1): 96-99.
Sykes,
W.H. (1839). On the fishes of the Deccan. Proceedings of the General Meetings for
Scientific Business of the Zoological Society of London1838(6): 157–165.
Sykes,
W.H. (1841). On the fishes of the
Dukhun. Transactions of the Zoological Society of
London 2: 349–378.