851 



Abstract— The bastard grunt 'Pomada- 

 sys incisus) is one of the most abundant 

 coastal demersal fishes inhabiting 

 the Canary Islands. Age and growth 

 were studied from samples collected 

 between October 2000 and September 

 2001. Growth analysis revealed that 

 this species is a fast growing and 

 moderately short-lived species (ages 

 up to seven years recorded). Length- 

 at-age was described by the von Ber- 

 talanffy growth model (L_=309.58 mm; 

 A=0.220/year; ((,=-1.865 year), the 

 Schnute growth model (>'j= 126.66 mm; 

 .V2=293.50 mm; a=-0.426; 6= 5.963), 

 and the seasonalized von Bertalanffy 

 growth model (L„=309.93 mm; k=0:218/ 

 year; <„= -1.896 year; C=0.555; (^=0.652). 

 Individuals grow quickly in their first 

 year, attaining approximately 60% of 

 their maximum length; after the first 

 year, their growth rate drops rapidly 

 as energy is probably diverted to repro- 

 duction. The parameters of the von 

 Bertalanffy weight growth curve were 

 W, =788.22 mm; *=0.1567/year; <„= 

 -1.984 year Fish total length and otolith 

 radius were closely correlated, r'^=Q.912. 

 A power relationship was estimated 

 between the total length and the oto- 

 lith radms (a=49.93; v'=0.851). A year's 

 growth was represented by an opaque 

 and hyaline (translucent) zone — an 

 annulus. Backcalculated lengths were 

 similar to those predicted by the growth 

 models. Growth parameters estimated 

 from the backcalculated sizes at age 

 were L_=315.23 mm; ft=0.217/year; and 

 (q= -1.73 year 



Age and growth of the bastard grunt 

 (Pomadasys incisus: Haemulidae) inhabiting 

 the Canarian archipelago. Northwest Africa 



Jose G. Pajuelo 



Jose M. Lorenzo 



Departament of Biology 



University of Las Palmas de Gran Canaria 



Campus Universitano de Tafira 



35017 Las Palmas de Gran Canaria, Spam 



E-mail address (for J G Pajuelo) |paguelo@dbio.ulpgc.es 



Muriel Gregoire 



Faculty of Biology 



University of Liege 



Liege, Belgium 



Present address: Departament of Biology 



University of Las Palmas de Gran Canaria 



Campus Universitano de Tafira 



35017 Las Palmas de Gran Canaria, Spain 



Manuscript approved for publication 

 19 June 2003 by Scientific Editor 



Manuscript received 26 June 2003 



at NMFS Scientific Publications Office. 



Fish. Bull. 101:851-859 (2003). 



The family Haemulidae consists of 

 16 genera (126 species), including 

 the genus Pomadasys, This genus is 

 represented by 37 species distributed 

 around the world. Members of this 

 family are commonly referred to as 

 grunt (Bauchot and Huraeu, 1990). 

 Only the bastard grunt (Pomadasys 

 incisus (Bowdich, 1825)) is found off the 

 Canary Islands. The bastard grunt is a 

 coastal demersal fish species inhabiting 

 marine and brackish waters along the 

 eastern central Atlantic coasts from the 

 Strait of Gibraltar to Angola, and also 

 in the Canaries, Azores, and Cape Verde 

 Islands (Bauchot and Hureau, 1990). In 

 the Canary Islands, where the bastard 

 grunt is one of the most abundant spe- 

 cies, it has been observed in high densi- 

 ties in schools along coastal waters. 



Information on the biology of the 

 bastard grunt is not available any- 

 where in the world. Despite its wide- 

 spread occurrence, the bastard grunt 

 has no commercial value for its low 

 quality meat and it is discarded in the 

 Canarian archipelago. The need for a 

 biologically based discard management 

 strategy and the paucity of data avail- 

 able on the biology of this species have 

 prompted an investigation into aspects 

 of its life history. We report aspects of 

 age and growth, which are important 



parameters in models for managing 

 the population of the bastard grunt off 

 the Canary Islands. 



Materials and methods 



A total of 878 individuals of P. incisus 

 were collected at weekly intervals from 

 discarded commercial catches taken 

 between October 2000 and September 

 2001 off Gran Canaria (Canary Islands, 

 central-east Atlantic, 27°57'24"N- 

 15°35'23"W). 



Each fish was measured to the nearest 

 mm for total length (L,) and weighed to 

 the near 0.1 g for total body weight (Wp. 

 Sex was assessed visually and sagittal 

 otoliths were removed, cleaned, and 

 stored dry for later age determination. 



Age estimation was made by identify- 

 ing and counting annuli following Wil- 

 liams and Bedford (1974). An annulus 

 was defined as a hyaline zone formed 

 annually in the winter season when 

 there is low growth and an opaque zone 

 formed annually in the summer season 

 when there is increased growth. The 

 whole otoliths were placed in a black- 

 ened bottom watch glass containing 

 water and examined under a compound 

 microscope (lOx) with reflected light. 

 Counts of the growth bands were made 



