5. Morphological description:
Body moderately elongated.
Dorsal profile more convex than the ventral
profile.
Snout obtuse, projecting over the mouth,
without any lateral lobe.
Eyes are small, not visible from the
underside of the head.
No pores on the snout.
Mouth small, inferior, lips thick and fringed
with a distinct inner fold to each lip.
Post labial grove continuous.
6. Morphological description
A cartilaginous part is covering to inside of both lips.
A pair of short maxillary barbells is present.
Body color is back brownish, silvery on sides and beneath.
Dorsal and abdominal profiles are convex. Caudal peduncle is short.
Lateral line is complete. Scales are moderate. The description is quite
similar to Rahman, 2005; Talwar and Jhingran, 2001 and Bhuiyan, 1964.
Fins greyish or dark, pectoral fin dusky. Color varies in fishes, those living
among weeds exhibiting greenish- black on back (Talwar and Jhingran
1991.)
Fin formula: D. 3/12-13, P1.16-17, P2. 9. A. 2/5 (Rahman, 2005)
7. Habit and Habitat
Labeo is column feeder at mid water. Prefers to feed on plant
matters including decaying vegetation (Talwar and Jhingran
1991.)
Its food comprises crustaceous and insect larvae in early
stages (Mookerjee et al., 1946).
Labeo rohita takes small percentages of mud which contains
organic matter and various salts. This species is available
throughout Bangladesh. Ponds, rivers, rivulets are its main
habitats (Bhuiyan, 1964).
8. Food and Feeding
Carp are omnivorous, and their diet varies
depending on what is available.
Food of Rohu may contain algae, higher
plants, protozoans, insect larvae,
crustaceans, mud and sand (Mukherjee, et
al., 1946)
In culture condition the species also feeds on
supplementary fish food, namely rice bran,
wheat bran and oil cake (Rahman, 2005).
9. Reproduction
It can be induced to breed by administration of pituitary
hormone when artificial culture.
Spawning season generally coincides with the south-west
monsoon (May to July)
It spawns in the shallow water of the river and streams.
Usually attains sexual maturity in 3 years.
It is a prolific breeder and fecund from 260,972 to
29,84,024 eggs (Rahman, 2005)
10. Distribution
Fresh water bodies of North and Central
India, Pakistan, Bangladesh; the Terai
region of Nepal and Myanmar. It has
been introduced in many countries,
including Bhutan, Mainland China,
Japan, Madagascar, Malaysia, Mauritius,
Philippines, Sri Lank, Thailand, Vietnam
and Zimbabwe.
11. Breeding time
Rui attains maturity towards the end of the second year in
ponds.
The spawning season of Rui generally coincides with the
southwest monsoon.
Spawning takes place in flooded rivers (Bhuiyan, 1964).
12. Economic Importance
Rohu is the most abundant among the species
of Genus Labeo, a commercially important
species and preferred as a food fish throughout
the Bangladesh and other countries.
Rui is regarded an excellent game fish and
seems to put up a better fight in a river than in a
tank.
A number of inter specific and inter generic
hybrids have been produced.
It is very delicious food and supplies a huge
amount of protein for the people (Rahman,
2005)
13. Ecological Role
Middle dweller fish species. Sometimes come to the
surface and bottom layer for finding food (Bhuiyan, 1964)
L. Rohita is a column and bottom feeder and feeds mainly
on plant matter and decaying vegetation and does not
compete with other carps for food and space.
14. Status and conservation
Very common and widely distributed species in
Bangladesh. Not considered as threatened in the red list
IUCN Bangladesh (2000).
L. rohita along with other members of the major carps used
to contribute over 60% of the total catch from river, bills and
Haors of Bangladesh during the mid- 1950s.
The major part of the carp catch currently comes from
aquaculture.
15. Marketing status:
Almost all the rohu produced from aquaculture is consumed in local markets.
Post-harvest processing is almost non-existent. Rohu is a highly preferred
carp and fetches comparatively high market prices.
In most areas, they are either marketed fresh in the local market or carried to
nearby urban markets with ice.
However, locally-produced fresh fish fetches about one and half times higher
market price than iced fish.
Furthermore, when sold live, the market value increases over two-fold
compared to iced fish. Governmental regulation and control over the
domestic marketing system for these aquaculture products are almost non-
existent; thus the market price is influenced mainly by demand and supply.
16. Remarks
There is a proverb, “Macher Raja Rui, Saker Raja pui”
There is long tradition of its use a delicious food item in the
matrimonial function of the Hindus in Bangladesh.
The fish a long live span of 10 years.
It is also good game fish.
The species is also infected by four species of
ectoparasites of the genus Lernaea.
17. Reference
Encyclopedia of FLORA AND FAUNA OF BANGLADESH, Freshwater
fishes, volume 23.
Fresh water fishes of Bangladesh, A.K Ataur Rahman, 2005
Fish and fisheries, Pandey, Shukla, 2nd edition.
www.en.wikipedia.org/wiki/Rohu
http://en.bdfish.org/2010/02/rohu-labeo-rohita/
http://www.fao.org/fishery/culturedspecies/Labeo_rohita/en#tcNA0078