The lined, or bluebanded, or clown surgeon is a striking surgeonfish with horizontal, black-edged blue stripes interspersed with yellow, and bluish-grey underside. The pectoral fins are pale with dusky rays; the pelvic fins light yellowish brown with black outer margin; the caudal fin has vertical markings.
The lined surgeon attains a length of 38 cm.
The body is covered with minute scales. The dorsal fin has 9 spines and 27-30 soft rays, the anal fin 3 spines and 25-28 soft rays. There is an erectile spine on each side of caudal peduncle, which is sharp, strong, forward-pointing, and venomous, and can cause painful wounds.
There is no specific information available about the life span of this fish, but it is not known to live beyond 18 years.
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This is a common species found across the coral reefs of Maldives.The fish is territorial, with a large male defending a feeding territory and a harem of females. The adults may also school, and they gather en masse during spawning. The juvenile is solitary. Their intraspecific behavior includes swimming, circling and provoking or chasing other fishes. Body color, including the caudal fin color pattern, changes with excitement; central area commonly turning black to white. In a school, there are generally one territorial male with several females.
Lined Surgeonfish is generally herbivorous. In its natural habitat, it feeds on marine algae and occasionally on meaty bits available in its surroundings. It generally feeds on sea-weeds and veg-based sources of foods.
Group spawning takes place with the females releasing spawn into the water table and the dominant male fertilizing the eggs. Once the eggs hatch the larvae go through a planktonic stage before settling down.
These fishes breed throughout the year. However, peak season for breeding is from October to February. This fish grows at a fast pace, reaching 70-80% of their total growth in the first year itself.
The Striped Surgeonfish is a popular aquarium species but a large tank is necessary because the species grows to 38 cm in length.
Acanthurus lineatus inhabits inshore coral reefs or rocky substrata exposed to wave action. It is strongly site-attached (Craig et al. 1997). It is most frequently encountered on shallow reef flats (Brown and Allen 2008). It is an aggressive territorial fish. It grazes on algal turfs mainly on thallate and filamentous red and green algae (Choat et al. 2002, 2004). It maintains feeding territories in shallow waters during the daytime but spends nights in deeper-water crevices where it is harvested by fishermen (Craig et al. 1997). Craig (1996) found that territorial and non-territorial A. lineatus where different individuals, with territorial fish being significantly larger.
It shows rapid growth for the first three to four years of life. Beyond four years, growth declines sharply; resulting in extended periods of asymptotic growth. Most of the growth occurs within the first 10% of their lifespan regardless of their location (Mutz 2006). The maximum number of annuli recorded for this species was 46 (Choat and Axe 1996). Maximum age was 42 years (Choat and Robertson 2002). On Great Barrier Reef, Australia (GBR), the mean maximum age is 32 years, on American Samoa is 11 yrs and on Marquesas is 14 yrs. The maximum age decreases moving eastwards (Mutz 2006).
Mutz (2006) investigated the pattern of demographic variation along a longitudinal scale across the South Pacific Ocean. The variation from west to east indicated locality specific variation rather than a general environmental trend among study sites. The population with the shortest lifespan was at American Samoa with a mean maximum age of 11 years, while the population at Lizard Island lived longest reaching the mean maximum age of 32 years. Populations at Moorea, French Polynesia and Lizard Island attained maximum ages of 43 and 42 years, respectively.
The sexes are separate among the acanthurids (Reeson 1983). Acanthurids do not display obvious sexual dimorphism, males assume courtship colours (J.H. Choat pers. comm. 2010). It spawns year-round but primarily during the austral summer (October-February) in American Samoa (Craig et al. 1997). This species has been observed in early morning group spawning in Palau and Guam (Johannes 1981, Robertson 1983, J. McIlwain pers. comm. 2010) and late afternoon group spawning at Escape Reef, Great Barrier Reef (Robertson 1983). It is likely to form resident spawning aggregations (Domeier and Colin 1997). Pair spawning (Robertson 1983) and non-sex-specific color changes associated with spawning (Johannes 1981) have also been observed. In Palau, it was observed to spawn prior to the full moon and during the new moon from February-April. In Guam it was observed to spawn 3 days before the full moon in March-April on the outgoing tide (J. McIlwain pers. comm. 2010). In the GBR it spawns in December (Johannes 1981, Robertson 1983). Size at sexual maturity is 160 mm (Choat and Robertson 2002a). Larvae are transported through pelagic waters while adults live sedentary lives associated with the reef (Robertson 1983). It has a long pelagic larval stage (Randall 2005).