Biology of Horadandia atukorali Deraniyagala, 1943 (Cyprinidae: Teleostei), an ornamental fish of theWestern Ghats of India
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Department of Fisheries Resource Management
Abstract
ABSTRACT
Horadandia atukorali, Deranyagala, 1943 is a small cyprinid (danionid) fish
distributed in southern India and Sri Lanka, which is an indigenous ornamental
fish of the Western Ghats of India.
A total number of 1254 specimens were used for investigating the different
aspects of biology. Sampling was done from January 2013 to December 2013
from two locations (location I, Panangad ponds and location II, Ezhupunna
wetlands).
The morphometric and meristic studies were conducted. 21 body
measurements were expressed as percentage of standard length and 4 head
measurements were expressed as percentage of head length and the relationships
were significant. The percentages of morphometric characters show in two
locations show slight variations, where as the meristic counts remained the same.
Maximum Total length was 3.5 cm in location I and 3 cm in location II.
Length weight relationship, condition factor and relative condition factor
were studied for males, females, juveniles and pooled in both locations. They
showed negative allometric growth. The b values of females were higher than the
males which suggested that females gained weight at a faster rate in relation to its
length than males. The overall condition of the fish was found to be in good
condition.
The oocyte development was classified into 9 oogenic stages. The
dominance of females over males has depicted in the monthly sex ratio (1:3.4).
The gonads were quantified into 5 maturity stages based on external morphology.
The size at first maturity was found to be 1.5 cm TL for females and 1.3 cm for
males. Ovaries of H. atukorali showed asynchronous development, in which
oocytes at all stages of development were present in the same ovary at the same
time. Ova diameter studies revealed that this species comes under the category C
299
of Karekar and Bal’s classification (1960), characterized by spawning more than
once during a protracted spawning season. Based on spawning frequency study of
the ripe ovary, H. atukorali was found to be a multiple spawner, with a protracted
spawning season, with peak spawning activity in November. The absolute
fecundity ranged between 22 (TL. 1.4 cm and 0.034 g body weight) and 172 eggs
(TL. 3.5 and 0.15 g body weight). They did not exhibit clear cut sexual
dimorphism.
The possession of a terminal mouth with moderate gape suggested that it is
a column feeder. They belonged to the group of stomach-less fishes in which the
digestive tube consisted of mouth, pharynx, oesophagus, intestine and anus. It is a
column feeder, mainly a carni-omnivore as well a micropredator feeding on small
insects, worms, crustaceans and other zooplanktons along with small amount of
phytoplankton. The relative gut length were calculated in males, females and
juveniles and it ranged between 0.6 and 0.95 in males, 0.5 and 0.7 in females and
0.5 and 0.7 in juveniles respectively.
Complete information on its reproductive biology and food and feeding
habits will definitely help in the commercial production and selective breeding
under captive condition. This will increase the domestic and export market of this
indigenous ornamental fish. It will also help in the conservation and management
of the species and their habitat.
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Keywords
Biology, Horadandia, atukorali, Deraniyagala, 1943 (Cyprinidae: Teleostei),