The biology of the sparid fish, Pachymetopon grande, was investigated from data collected on the southeastern Cape coast between August 1984 and March 1987. Sectioned sagittal otoliths revealed that they are a slow-growing, long-lived species capable of reaching ages in excess of 40 years. Detailed histological examination of gonadal development showed that they are rudimentary hermaphrodites, males and females maturing after a non-functional intersexual stage. The breeding season is restricted to between January and June, and observations suggest that they are group spawners with pelagic eggs. Maturity was reached at 300 mm fork length or approximately 5,5 years old. P. grande is primarily herbivorous, feeding selectively on rhodophytes found on inshore reefs down to approximately 20 m. Minor dietary components included hydrozoans, octocorals and other small invertebrates. Macroalgal degradation by gut endosymbionts or the utilization of macroalgal epibionts was not evident, suggesting that storage and extracellular carbohydrates of the macroalgae were utilized in the diet. The importance of P. grande to the inshore recreational angling fishery, together with certain aspects of its biology, underline the need for conservation measures aimed at ensuring the sustainability of this resource.

Aspects of the biology of the musselcracker Sparodon durbanensis, an important shore-angling species on the south-eastern coast of South Africa, are described from material collected between August 1984 and March 1987. Juvenile fish live in tidal pools and in shallow subtidal waters, where they feed on a variety of small invertebrates and chlorophytes. Larger fish are more common in deeper water down to about 30 m, but they also feed inshore, consuming large invertebrate prey such as gastropods, pelecypods, solitary ascidians, crustaceans and amphineurans. They are rudimentary hermaphrodites, mature at approximately 350 mm fork length and have a restricted breeding season between August and January, during which period they spawn small pelagic eggs. Growth studies based on sectioned sagittal otoliths reveal musselcracker to be slow-growing and long-lived, that both sexes grow at a similar rate and that they can survive to at least 31 years of age. The species is likely to be highly susceptible to overexploitation even though the fish are not commercially exploited, and more stringent management measures are called for to ensure the survival of the species as a recreational angling resource.

A recreational rock-angling fishery on South Africa's Eastern Cape coast was studied on the basis of random sampling which aimed at removing the sample bias usually associated with such studies. The fishery is primarily recreational and catch per unit effort is low (202,1 g·angler-hour−1). A total of 27 teleosts was recorded, the most important of which were Pomatomus saltatrix (74,7 g·h−1), Sparodon durbanensis (30,3 g·h−1), Diplodus sargus capensis (19,4 g·h−1) and Pachymetopon grande (12,6 g·h−1). Seven cartilaginous species were caught, of which Mustelus mustelus (16,6 g·h−1) was the most important. Sharks were either discarded or returned to the sea. Catches of most species were seasonal, a result of both availability of fish and targeting of angler effort. Despite considerable overlap in the catch between this and the commercial sector of the linefishery, a number of species may be considered primarily recreational. Management of such species is discussed and the importance of long-term data series to the management of the resource is recognized.

The sparid Pachymetopon aeneum is a benthic carnivore feeding predominantly on hydroids, tunicates and octocorals. Juveniles and subadults occur on shallower reefs than the adults but the diet of all sizes is similar. The species is a protogynous hermaphrodite, sex reversal occurring between 200 and 300 mm forklength. Fifty per cent maturity in females occurs between 200 and 250 mm forklength. Peak reproductive activity was recorded between September and March. Otoliths were used to determine growth rate. Growth in length was described by the equation, Lt(Mmm) = 467,06(1 -e-0,1328(t-0,2473)). The relationship between length and weight, W(g) = 0,00001L(mm)3,149, was used to determine somatic growth as, Wt(g) = 2545,98(1 - e-0, 1328(t-0, 24731))3,149. p. aeneum have a potential for exploitation but the combination of late maturation and protogynous hermaphroditism could lead I to over-exploitation in a size-selective fishery.

Stomach contents of fish taken between Mossel Bay and Algoa Bay were analysed. Prey associated with both hard and soft substrates were present in the diet although the latter were more Important. The mouth structure Is shown to be well adapted to feeding over soft substrates.Maaginhoudanalises is gedoen van vis wat gevang is tussen Mosselbaai en Algoabaai. Prooi wat geassosieer word met riwwe sowel as sand was teenwoordig in die dieet, alhoewel laasgenoemde belangriker was. Die mondvorm is goed aangepas vir voeding oor sand.