The yellow pufferfish, Xenopterus naritus is a commercially important target species for the
artisanal fishermen in Sarawak. There is concern over its conservation and population structure.
Therefore we provided a baseline data on size distribution, sex ratio, length-weight relationship and
condition factor of 65 specimens of this species, landed from May 2015 to July 2014 from eight distinct
locations (Kabong, Sematan, Buntal, Paloh, Sadong Jaya, Pusa, Sebangan and Spaoh) representing the
Southwest coast of Sarawak waters. Specimens were obtained by hiring local fishermen to catch them
and purchasing from fish markets. Generally, males were significantly smaller and lighter than females.
Total length, standard length and body weight of combined sexes of X. naritus was found in the size
range of 10.6–29.5 cm, 8.8–26.7 cm and 20.16–646.76 g respectively. Male to female sex ratio was
1M:2.8F. Length–weight relationships of X. naritus exhibited positive growth allometry in males but
negative growth allometry in females, whereas positive growth allometry in combined sexes. Condition
factor in overall specimens was 2.279±0.434 which reflects the healthiness of X. naritus and favorable
environmental conditions in Sarawak waters. Findings of the present study contribute as important
baseline data for future studies not only on the fisheries and stock management of X. naritus but also on
conservation and aquaculture development of this commercially important species
