Phenotype and genotype characterization, feeding habit and reproductive biology of crossbanded barb, Puntioplites bulu (Bleeker, 1851) from Peninsular Malaysia
Puntoplites bulu is a freshwater Cyprinidae and widely distributed in Southeast Asia. It has attracted considerable interest due to high demand and price. However, an apparent decline in its distribution and abundance is observed and this is due to several factors, such as habitat degradation, po...
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| Format: | Thesis |
| Language: | English |
| Published: |
2019
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/85501/1/FP%202020%2033%20ir.pdf |
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| Summary: | Puntoplites bulu is a freshwater Cyprinidae and widely distributed in Southeast
Asia. It has attracted considerable interest due to high demand and price.
However, an apparent decline in its distribution and abundance is observed
and this is due to several factors, such as habitat degradation, pollution and
overfishing. Little is known about the biology and population structure of this
valuable freshwater species. Therefore, this study was to investigate its
population morphological difference, genetic diversity, reproductive biology
and feeding guild of P. bulu in Peninsular Malaysia.
Meristic, morphometric characters and truss network analysis were used in
discriminant analyses to study the intraspecific variation of wild P. bulu stock
from three major rivers (Perak River, Pahang River and Kelantan River) in
Peninsular Malaysia. Morphometric characters variations were apparent with
samples from Perak River and were found to have longer pre-occipital length,
pre-operculum length and caudal peduncle length, while samples from
Kelantan River were found to have longer length from pelvic fin base to anal
fin base. Further, based on truss network analysis, differences were observed
mainly on head and caudal region with samples from Perak River population
had smaller head and longer caudal area.
Intraspecific variation of P. bulu from the three major rivers was also
determined based on genetic divergence by using mitochondrial DNA
(mtDNA). Two distinct genetic lineages were apparent viz Central West and
East Peninsular Malaysia with natural barriers (the Titiwangsa Range) acted
as natural dividers between these two lineages. Alternatively, the close genetic
relation and haplotype sharing that were observed between Perak and Kelantan populations could be due to human translocations. Further,
haplotype sharing between Kelantan and Pahang populations revealed the
migration ability of P. bulu through ancient connectivity.
Food items of P. bulu from Perak River revealed a planktivorous feeding
habits. They consumed more plant matter based food item with
Bacillariophyceae as the major diet item based on a simple resultant index of
29.9%, Crustacea (21.26%), Chlorophyceae (10.6%), detritus (14.88%),
Mollusca (12.65 %) plant matter (9.92%), and worms (0.8 %). High food
overlap was observed between adult and juvenile stages, although
ontogenetic dietary changes were observed between these two stages with
adults consuming a larger prey size while juveniles feed primarily on smaller
items.
Some aspects of reproductive biology of P. bulu were determined from the
Perak River. Asynchronous ovarian development patterns were observed and
spawning season happened in October and May, coincided with rainfall
period. The sex ratio of P. bulu during the study period was 1:1.14, though the
females predominated in almost every month. Mature size for females and
males was in the range of 25-30 cm and 20-25 cm, respectively. Absolute
fecundity ranged from 1,631 to 31,059 per ovary and it was highly related to
ovary weight and gonadosomatic index (GSI) rather than body weight and total
length.
In conclusion, morphological divergence and two distinct genetic lineages of
P. bulu were observed between the three major rivers in Peninsular Malaysia.
They are planktivorous and had an asynchronous ovary development pattern
with spawning season coincided with rainfall. Information from this study
useful to facilitate the management of this valuable species. |
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