Biology
Banded Morwong is a large, sedentary fish that inhabits temperate reefs around south-eastern Australia and New Zealand (Gomon et al 2008). In Australia, the species distribution extends from Sydney, through Victorian and Tasmanian waters, to eastern South Australia. The species has occasionally been observed in Western Australia. Banded Morwong are long-lived, and can reach ages of at least 97 years (Ewing et al. 2007). While longevity is similar among sexes, the species displays strong sexual dimorphism in growth, with males growing substantially faster and reaching larger maximum sizes than females (Ziegler et al. 2007a).
The stock structure of Banded Morwong in Australian waters is presently undefined, however observations of a long pelagic larval stage (around 6 months; Wolf 1998) suggests that single genetic stocks may occur over large areas. After settlement, fish are relatively sedentary, with tagging studies indicating little exchange among reefs (Murphy and Lyle 1999).
| Parameters | Estimates | Sources |
|---|---|---|
| Habitat | Rocky reefs down to 50 m depth. Females and juveniles inhabit the shallow section of the reef while males dominate in the deeper section of the reef. | McCormick (1989a, b) |
| Distribution | South Sydney (New South Wales) through Victoria and Tasmania to eastern South Australia, also in New Zealand. | Gomon et al. (2008) |
| Diet | Invertebrates, algae, crabs | McCormick (1998) |
| Movement and Stock Structure | Limited movement of juveniles and adults, generally restricted to within 5 km of the release site. No information on the stock structure. | Murphy and Lyle (1999); Ziegler et al. (2006); Buxton et al. (2010) |
| Natural Mortality | Low. Estimated at M = 0.05. | Murphy and Lyle (1999) |
| Maximum Age | Females: 94 years Males: 97 years | Ewing et al. (2007) |
| Growth | Males grow to larger sizes than females. Growth described by the Schnute and Richards (1990 growth function: ? = ?∞(1+ ??(−???))−1? where L is the length (mm), t is the age (years), ?∞ is the average maximum length for the species and α, a, b and c are (year-specific) constants. Parameters estimates (for 2007) are: Sex________ ?∞____a_______ b_________c_______α Female____442_____18.8____3.3e-7_____0.05___51.4 Males_____516______2.3_____0.0088____0.33___0.1 Length-weight relationship for 2007 was estimated at ? = 3.563?−5?2.875 for females and ? = 3.729?−5?2.852 for males, where W is weight (g) and L is the fork length (cm). | Schnute and Richards (1990); Ziegler et al. (2007a) |
| Maturity | Size-at-50% maturity estimated at 320 mm for females (~2.5 years of age). | Ziegler et al. (2007a) |
| Spawning | Spawning occurs between mid February to late May. Species is a serial spawner. | Murphy and Lyle (1999) |
| Early Life History | Eggs and larvae are concentrated on the surface. Banded Morwong has a pelagic larval stage that is distributed offshore, as suggested by the large amounts of larvae caught off the shelf break of eastern Tasmania. Juveniles appear in shallow water on rocky reefs and tide-pools between September and December, after a pelagic phase of 4-6 months. | B. Bruce, pers. comm. Wolf (1998) |
| Gillnet Post Release Survival | High: 97% irrespective of gillnet soak duration | Lyle et al. (2014a) |
