Ž .
Aquaculture 193 2001 123–137 www.elsevier.nlrlocateraqua-online
Feeding rates and scope for growth of green ž
mussels, Perna Õiridis L. and their relationship with food availability in Kat O, Hong Kong
W.H. Wong, S.G. Cheung
Department of Biology and Chemistry, City UniÕersity of Hong Kong, 83 Tat Chee AÕenue, Kowloon, Hong Kong SAR, People’s Republic of China
Received 28 March 2000; received in revised form 10 July 2000; accepted 10 July 2000
Abstract
Ž .
Ž . The feeding and absorption rates ARs of the green mussel Perna Õiridis L. were studied
from December 1997 to November 1998. During each visit, characteristics of seston including Ž
. Ž
. concentrations of total particulate matter TPM , particulate organic matter POM , particulate
Ž .
Ž . inorganic matter PIM and organic fraction of seston f were also determined. Higher values of
Ž .
Ž .
clearance rates CRs , ARs and absorption efficiencies AEs were obtained from November to January and lower values in March and April. CR was a negative power function of TPM and a
positive linear function of f. ARs and AEs were significantly correlated with TPM and f Ž
. Ž
. P - 0.001 , showing that food availability both seston quantity and quality was the key factor
influencing feeding behaviour of P. Õiridis. The activity of amylase and cellulase in the digestive Ž
. gland and crystalline style, and the scope for growth SFG were determined in February, May,
July and October to represent the situation in winter, spring, summer and autumn, respectively. There was no correlation between digestive enzyme activities and seasons except for amylase
activity in the digestive gland. SFG was lowest in February and highest in October, and was correlated with f. q 2001 Elsevier Science B.V. All rights reserved.
Keywords: Mussels; Perna Õiridis; Feeding; Scope for growth; Food availability
1. Introduction
The green mussel Perna Õiridis is widely distributed in tropical and sub-tropical areas of the Indo-Pacific region. Its dramatic growth and natural abundance have
Corresponding author. Tel.: q86-852-27887749; fax: q86-852-27887406. Ž
. E-mail address: bhsgchecityu.edu.hk S.G. Cheung .
0044-8486r01r - see front matter q 2001 Elsevier Science B.V. All rights reserved. Ž
. PII: S 0 0 4 4 - 8 4 8 6 0 0 0 0 4 7 8 - 6
encouraged efforts to culture this species as a cheap protein source in this region which Ž
. Ž
. includes China Menzel, 1988 , Singapore Cheong and Lee, 1981 , the Philippines
Ž .
Ž .
Ž Walter, 1982 , Thailand Chalermwat and Lutz, 1989 and India Rajagopal et al.,
. Ž
1998 . In Singapore, P. Õiridis accounted for 70.4 of aquaculture production Chou .
and Lee, 1997 . After China, Thailand is the second largest producer of mussels in Asia with nearly 35,000 ha of coastal area that are suitable for mollusc culture, and P. Õiridis
Ž yields the highest net profit of any bivalves cultured in the country Chalermwat and
. Lutz, 1989 . In Hong Kong, P. Õiridis is distributed widely from oceanic waters to
estuarine waters. It is a dominant intertidal and subtidal species and highest densities Ž
2
. Ž
have been recorded from Victoria Harbour 246 per m and Tolo Harbour 1000 per
2
. Ž .
m Huang et al., 1985 . Although this species is not intentionally cultured in Hong
Kong, their abundance on fish cages is so great that they are collected by fish farmers as Ž
. a byproduct. Its high density and fast growth rate in Hong Kong Cheung, 1991
demonstrates the potential of P. Õiridis as an aquaculture species. Although this species plays an important economic role in southeast Asia, information on the relationship
Ž .
between feeding physiology and food availability is limited Hawkins et al., 1998a . A recent approach to developing a sustainable aquaculture industry is to use ecosystem
Ž modelling to determine the carrying capacity of the environments Grant et al., 1993;
. Heral, 1993; Dame, 1996; Bacher et al., 1998 . The first step in this approach is to
´
understand the inter-relationship between food availability and feeding response of the Ž
aquaculture species Stenton-Dozey and Brown, 1994; Bacon et al., 1998; MacDonald et .
al., 1998 . In this experiment, the physiological parameters of feeding in P. Õiridis Ž
. Ž
. which included clearance rate CR , absorption rate AR and absorption efficiency
Ž .
AE , and their relationships with food availability in the experimental water column were studied at Kat O, the site with the fastest growth recorded for P. Õiridis in Hong
Kong. The results may help in the calculation of the carrying capacity for this potential Ž
culture site and in the selection of culture sites in different waters of Hong Kong Lee, .
1986; Cheung, 1991 .
2. Materials and methods
