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12 Marine Fisheries Information Service T&E Ser., No. 196, 2008
Table 6. Sex-ratio (Male: Female) and length at first maturity
(L m
) of important species
Species Sex ratio Length at
first maturity
S.longiceps 1:0.8 16.0
S.gibbosa 1:0.9 14.5
R.kanagurta 1:1 19.7
T.albacares 1:0.5 93
T.lepturus 1:1.4 37.0
N.japonicus 1:0.7 12.8
S.undosquamis 1:0.9 23.0
U.vittatus 1:1.5 13.8
J.carutta 1:1.8 15.4
O.ruber 1:1.2 -
M.monoceros 1:1.5 9.5 (m)
11.5 (f)
M.dobsoni 1:1.2 6.8 (m)
8.8 (f)
P.sanguinolentus 1:1.9 9.0 (f)
to natural ecological changes. In Andhra Pradesh,
the fishery is sustained mainly by finfishes and
crustaceans. Of the thirteen species of finfishes and
crustaceans studied twelve are being exploited at
levels higher than that desired (Table 8). Comparison
with earlier studies has shown that the mean length
as well as the length at first maturity has reduced
over the years. These facts indicate that there is great
pressure on the commercially important fish and
prawn species. These disturbing facts call for adoption
of conservative measures to ensure long term
sustained fishery along the Andhra coast. The
government of Andhra Pradesh keeping this fact in
mind has been strictly imposing a fishing ban for 45
days from mid-April to May. However, certain other
measure like mesh size regulation, limiting the
number of different crafts, demarcation of fishing
grounds for different categories of boats, fishing
quota, etc., will have to be taken up to sustain the
fishery of commercially important fishes/crustaceans
at present levels and to increase the overall fish
Table 7. Length - weight relationship of major species
Species 'a' value 'b' value
Sardinella longiceps 0.012339 2.836
S.gibbosa 0.022806 2.6075
Rastrelliger kanagurta 0.003687 3.3623
R.faughni 0.00574 3.2043
T.albacares 0.00863 3.12
S.guttatus 0.023 2.782
Trichiurus lepturus 0.0006 3.05
J. carutta 0.00002145 3.0279
U.vittatus 0.013969 2.9899
S.undosaquamis 0.000003754 3.1025
M.monoceros Male:0.00635Female:0.003857 Male:2.9580Female:3.1936
M.dobsoni Male:0.007339Female: 0.010715 Male: 2.9477Female: 2.7870
P.sanguinolentus Male: 0.060253Female: 0.09415 Male: 2.9440Female: 2.7942
Fluctuations in catch is an inherent quality of any
tropical fisheries system, but steep decline in catch
of commercially important fishes especially, those
which are subjected to higher fishing pressure
(prawns, mackerel, ribbonfish, threadfin breams) is
not a healthy indicator for the fisheries system.
Fisheries being a renewable resource are fully
capable of recouping its stock back to healthy levels
under normal circumstances. However, of late it has
been noticed that steep decline in catch of certain
species is also due to human interference in addition
production of the state in the coming years. Of the
several limiting restrictions that will have to be
considered for implementation, the most important
measure will have to be on the number of units
operating in an area. The catch rates of major
resources especially those in the mechanized sector
are on a steady declining trend. It is observed that
the fishing effort in the coastal zone exceeds its
resource potential. Though the implementing agency
has not so far succeeded in bringing out certain
strictures to limit the number of units, the adverse