Parameters a and b of the length-weight relationship (LWR) were estimated for eleven species of mudskippers caught in the coastal areas of Selangor, Malaysia. The values of b ranged from 2.56 to 3.50 with the mean b equal to 2.95 (n=11; sd=0.302). A normal distribution of the calculated LWR exponent (b) was obtained

Khaironizam, M.Z.

Norma-Rashid, Y.

English

Aquatic Commons

Naga, WorldFish Center Quarterly (Vol. 25, No. 3 & 4) July-Dec 200220
Length-weight Relationship of Mudskippers
(Gobiidae: Oxudercinae) in
the Coastal Areas of Selangor, Malaysia
M.Z. Khaironizam and Y. Norma-Rashid
Introduction
Oxudercine gobies are euryhaline
fishes commonly referred to as
mudskippers. They are amphibious,
highly active during low tides and
spend most of their time out of water
in mangrove habitats. Mudskippers
are a delicacy among the people of
Taiwan and Japan and are highly
priced, selling for as high as US$20/
kg (Ip et al. 1990). The mudskippers
have a high density on tidal mudflats
that are formed in creeks and estuaries
and on mangrove forest floors.
Mangrove forests and their
waterways are important in
supporting the fish population
because they provide organic matter
and detritus as food sources
(Sasekumar and Chong 1998).
Ricker (1968) expressed the
importance of length-weight
relationships in population
assessments. Some examples of
studies on LWR include King 1996a;
Kulbicki et al. 1993; Garcia et al.
1998; Haimoivici and Velasco 2000.
A similar study on the mudskipper
Periophthalmus barbarus was
conducted by King and Udo (1996)
in Nigeria. Aspects of population
dynamics were investigated by King
(1996b) and Etim and Arntz (1996).
The objective of this paper is to make
available LWR parameters for
mudskippers caught in coastal waters
of Selangor, Malaysia.
Materials and Methods
Specimens were obtained from
intensive field samplings, conducted
from October 1998 to July 2000 in
the mangrove areas of the Selangor
coast (Fig. 1). Fishes were caught by
hand net on mudflats, riverine areas
and mangroves. The species
description given in Murdy (1989)
and Murdy and Takita (1999) were
used for taxonomic identification.
Fish samples were preserved in 10%
formalin and washed with water and
dried before measuring. The total
length (TL) and standard length (SL)
were measured to the nearest 0.1 mm
using a caliper. Fish were weighed to
the nearest 0.1 g.
The length-weight relationship
was calculated using the formula:
W= a·Lb ………….....…….(1)
and transformed to :
f
is
h
b
y
t
e
Abstract
Parameters a and b of the length-weight relationship (LWR) were estimated for eleven species of mudskippers
caught in the coastal areas of Selangor, Malaysia. The values of b ranged from 2.56 to 3.50 with the mean b equal
to 2.95 (n=11; sd=0.302). A normal distribution of the calculated LWR exponent (b) was obtained.
Fig. 1. Map showing the location of the study area.
La
tit
ud
e 
(0 N
)
Longitude (0E)
Naga, WorldFish Center Quarterly (Vol. 25, No. 3 & 4) July-Dec 2002 21
log W = log a + b log L….(2)
where b is an exponent with the value
nearly always between 2 and 4, and
often close to 3. The value b=3
indicates that the fish grows
symmetrically or isometrically
(provided its specific gravity remains
constant). Values other than 3 indicate
allometric growth: if b>3, the growth
is called positive allometric and if
b<3, it is called negative allometric.
Pauly (1993) reported that b values
must be equal to 3 if fishes have to
maintain their shape as they grow, but
there is no theory that says in which
case the estimated b values can be
expected to be negatively or positively
allometric. Garcia et al. (1998)
reported that biological interpretation
of the numerical values of the
parameters a and b is not
straightforward, except that when
growth is isometric, a can be
interpreted as a condition factor.
When growth is allometric, the role
of a as the condition factor is
questionable. The length-weight data
pairs were analyzed using ordinary
least squares regression (95%
confidence), using STATISTICA
version 5.0.
Results and Discussion
Results of the LWR analysis of
eleven species of goby are
summarized in Table 1. The b value
estimator indicates that
Periophthalmodon schlosseri and
Boleophthalmus boddarti followed
isometric growth, while
Periophthalmus argentilineatus,
Periophthalmus spilotus and an
unidentified species  indicated
allometric growth with positive
allometry (b>3.0).The rest of the
species exhibited negative allometry
(b<3.0). The mean b value from the
eleven species was 2.950 (n=11;
sd=0.302) and not significantly
different from b=3 (t-test; df=10,
p>0.05). Fig. 2 shows the normal
distribution of exponent  (b) of the
eleven species that were analyzed.
Acknowledgments
This work was partially funded by
PJP SF113/2000A for the first author
and R&D 09-02-03-0674 for  the
second author, both grants awarded
by University Malaya.
References
Etim, L., T. Brey and W. Arntz. 1996. A
seminal study of the dynamics of a
mudskipper (Periophthalmus papilio) in
the Cross River, Nigeria. Netherlands J.
Aquat. Ecol. 30(1): 41-48.
Garcia, C.B., J.O. Duarte, N. Sandoval, D.
von Schiller, G. Melo and P. Navajas.
1998. Length-weight relationships of
demersal fishes from the Gulf of
Salamanca, Colombia. Naga, ICLARM
Q. 21(3):30-32.
Haimoivici, M. and G. Velasco. 2000.
Length-weight relationship of marine
fishes from Southern Brazil. Naga,
ICLARM Q. 23(1):19-23.
Ip, Y.K., S.F. Chew, A.L.L. Lim and W.P.
Low. 1990. The mudskipper, p. 83-95.
In Essays in Zoology, Papers
commemorating the 40th Anniversary of
the Department of Zoology, National
University of Singapore.
King, R.P. 1996a. Length-weight
relationships of Nigerian freshwater
fishes. NAGA, ICLARM Q. 19(3):
49-52.
King, R.P. 1996b. Population dynamics of
the mudskipper Periopthalmus
barbarus (Gobiidae) in estuarine swamp
Species n Equation (W=a·Lb) r SL (mm)
Min Max
Periophthalmus chrysospilos 315 W= 6.546 x 10-5·SL2.56 0.982 18.2 83.2
Periophthalmus gracilis 110 W= 3.296 x 10-5·SL2.80 0.974 20.5 42.7
Periophthalmus novemradiatus 299 W= 5.117 x 10-5·SL2.67 0.989 18.3 70.2
Periophthalmus argentilineatus 15 W= 4.375 x 10-6·SL3.34 0.990 43.0 71.6
Periophthalmus spilotus 29 W= 2.660 x 10-6·SL3.50 0.995 40.3 71.4
Periophthalmodon schlosseri 20 W= 1.766 x 10-5·SL3.06 0.989 79.5 207.0
Periophthalmodon septemradiatus 22 W= 2.710 x 10-5·SL2.90 0.969 47.1 68.5
Boleopthalmus boddarti 128 W= 1.556 x 10-5·SL3.00 0.977 30.0 128.4
Scartelaos histophorus 97 W= 4.325 x 10-5·SL2.62 0.984 32.8 81.2
Pseudapocryptes elongatus 84 W= 2.541 x 10-5·SL2.81 0.991 20.1 133.6
Unidentified species 70 W= 8.994 x 10-6·SL3.20 0.996 34.7 132.4
Table 1. Length-weight relationships and related statistics of mudskippers caught off
Selangor, Malaysia.
Fig. 2. Distribution of b values of the LWR for eleven species of mudskippers caught in the
coastal area of Selangor, Malaysia.
f
is
h
b
y
t
e
Naga, WorldFish Center Quarterly (Vol. 25, No. 3 & 4) July-Dec 200222
of Cross River, Nigeria. J. Aquat. Sci.
11: 31-41.
King, R.P. and M.T. Udo. 1996. Length-
weight relationships of the mudskipper
Periophthalmus barbarus in Imo River
estuary, Nigeria. Naga, ICLARM Q.
19(2):27.
Kulbicki, M, G. Mou Tham, P. Thollot and
I. Wantiez. 1993. Length-weight
relationships of fish from the lagoon of
New Caledonia. Naga, ICLARM Q.
16(2 & 3):26-30.
Murdy, E.O. 1989. A taxonomic revision and
cladistic analysis of the Oxudercine
gobies (Gobiidae: Oxudercinae). Rec.
Australian Mus. Suppl. 11:1-93.
Murdy, E.O. and T. Takita 1999.
Periophthalmus spilotus, a new species
of mudskipper from Sumatra (Gobiidae:
Oxudercine). Ichthyol. Res. 46(4):367-
370.
Pauly, D. 1993. Editorial Fishbyte section.
Naga, ICLARM Q. 16(2-3):26.
Ricker, W.E. 1968. Methods for assessment
of fish production in freshwaters.
International Biological Programme No.
3, Blackwell Scientific Publications,
London. 313 p.
Sasekumar, A. and V.C. Chong. 1998.
Faunal diversity of Malayan mangroves.
Global Ecol. Biogeo. Lett. 7:57-60.
M.Z. Khaironizam and Y. Norma-Rashid
are from the Institute of Biological Sciences,
Faculty of Science, University Malaya,
50603 Kuala Lumpur, Malaysia.
E-mail: zayon1410@hotmail.com


Length-weight relationship of mudskippers (Gobiidae: Oxudercinae) in the coastal areas of Selangor, Malaysia

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Length-weight relationship of mudskippers (Gobiidae: Oxudercinae) in the coastal areas of Selangor, Malaysia

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