International Journal of Aquaculture, 2017, Vol.7, No.15, 101-105
101
Research Report
Open Access
First Report of A Xanthic Phenotype of the Silver Carp,
Hypothalamichthyes
molitrix
(Valenciennes, 1844) (Teleostei: Cyprinidae) from Maharashtra Fish
Seed Production Centre, India
Rajkumar T. Pawar
1
, Laith A. Jawad
2
1 Department of Zoology, Sunderrao Solanke Mahavidyalaya, Majalgaon, India
2 Flat Bush, Manukau, Auckland 2016, New Zealand
Corresponding author Email:
International Journal of Aquaculture, 2017, Vol. 7, No.15 doi:
Received: 19 Jul., 2017
Accepted: 15 Aug., 2017
Published: 25 Aug., 2017
Copyright © 2017
Pawar and Jawad, This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Pawar R.T., and Jawad L.A., 2017, First report of a xanthic phenotype of the silver carp,
Hypothalamichthyes molitrix
(Valenciennes, 1844) (Teleostei:
Cyprinidae) from Maharashtra Fish Seed Production Centre, India, International Journal of Aquaculture, 7(15): 101-105 (doi:
Abstract
On 21st November 2016 and 4th January 2017, two specimens of silver carp
Hypophthalmichthys molitrix
(TL 750-762
mm, SL 610-470 mm) were reported for the first time from Maharashtra Fish Seed Production Centre, Maharashtra, India. This
condition of the skin, in which yellow coloration predominates is called xanthism. This is the first ever report of xanthism
H. molitrix
.
The yellow colour is covering the whole body of the two malformed specimens. Head, eyes and fins were having a faint orange
coloration. In the abnormal specimens, red to orange spots replacing the dark spots found in the normal specimens. Other deformities
such as distorted lateral line were noted in one of the abnormal specimens.
Keywords
Cyprinidae; Xanthism; Silver carp; India
1 Introduction
Many alien fish species have been illegally brought into India by private aquaculturists, entrepreneurs and
aqua-industrialists for immediate gains and several ponds and lakes were stocked with these species in the 1950s
(Singh and Lakra, 2011). The silver carp was introduced in 1959 with the aim to enhance the aquaculture sector
and increasing yields.
Silver carp
Hypophthalmichthys molitrix
(Valenciennes) is belong to the family Cyprinidae. It is originally
described as species of the genus Leuciscus and subsequently placed in the genus
Hypophthalmichthys
(Oshima,
1919). This species isnative to eastern Asia and has been broadly introduced to southern Asia, Europe and North
America (Kolar et al., 2007). It has a deep and spindle-shaped body, laterally compressed with a well-developed
keeled abdomen that extends from the throat to the vent (Figure 1). Adult coloration is typically gray-black
dorsally, upper sides olivaceous grading to silver laterally and ventrally. Fins are dark and without true spines;
however, in larger individuals the anterior ray of the pectoral fins is thickened, stiff and is finely serrated
posteriorly.
Several freshwater fish groups have shown variable cases of xanthism including members of the families
Centrachidae (Allen and Neill, 1953), Cichlidae (Webber et al., 1973), Cyprinodontidae (Turner and Liu, 1977),
Lepisosteidae, (McIlwain and Waller, 1972; Tyler, 1990), Percidae (Denoncourt 1976) and Poeciliidae (Angus
and Blanchard, 1991). The phenomena of xanthism have a genetic basis that explains the wide range presence
across a wide taxonomic spectrum (Angus and Blanchard, 1991). It characterised by a partial or predominant
yellow skin or integument colour that affects small parts of populations of some species (Smith, 1971, Béarez et
al., 2006).
The xanthic phenotype has an impact on the survival of the individuals bearing this case, where they are
conspicuous to the predator more than those individuals with normal coloration (Endler, 1980). This unfortunate
occurrence of visibility makes the xanthic individuals within each species rare (Turner and Liu, 1977;
Pattengill-Semmens, 1999).
