BRACHALUTERES JACKSONIANUS - (QUOY & GAIMARD, 1824)
Picture courtesy of: Alain Daoulas
Actinopterygii (Gigaclass) > Actinopteri (Class) > Teleostei (Subclass) > Tetraodontiformes (Order) > Balistoidei (Suborder) > Monacanthidae (Family) > Brachaluteres (Genus)
Pigmy leatherjacket, Pygmy Leatherjacket, Southern pygmy leatherjacket, Pez lija pigmea, 杰克逊短革鲀, 杰克逊短革单棘鲀,
Synonymes
Aleuterius baueri (Richardson, 1846)
Aleuterius trossulus (Richardson, 1846)
Balistes jacksonianus (Quoy & Gaimard, 1824)
Balistes lamouroux (Quoy & Gaimard, 1824)
Brachaluteres baueri (Richardson, 1846)
Brachaluteres fidens (Whitley, 1931)
Brachaluteres trossulus (Richardson, 1846)
Brachaluteres wolfei (Scott, 1969)
Monacanthus distortus (Castelnau, 1873)
Monacanthus oculatus (Günther, 1870)
---------------------------
Description
Dorsal spines (total): 1; Dorsal soft rays (total): 24-29 (usually: 26-28); Anal soft rays: 22-28 (usually: 24-25); Pectoral fin rays: 10-12 (usually: 11); Caudal fin rays: 12; Vertebrae: 20. Head length: 2.4-3.2, body depth: 1.1-1.5, snout length: 3.9-4.9, and length of soft dorsal fin base: 2.1-2.7, all in SL; Eye diameter: 2.6-3.9, gill slit length: 4.1-7.8, first dorsal spine length: 1.0-2.7, interdorsal space: 1.1-1.9, longest soft dorsal ray (eight to twelth): 2.6-3.6, and caudal fin length: 0.9-1.4, all in head length; Caudal peduncle generally prominent, length: 2.2-4.8 in head length and 1.2-2.0 in caudal peduncle depth. Small fish with an almost circular body; Large expandable ventral flap (dewlap); Abdomen greatly inflatable; Skin covered in velvety spinules; First dorsal fin a single smooth spine that cannot be locked in an erect position; Anal fin and second dorsal fin opposite, both with unbranched rays. Max. length: 10.0 cm TL. Depth range: 1 - 73 m.
Pigmy leatherjacket, Pygmy Leatherjacket, Southern pygmy leatherjacket, Pez lija pigmea, 杰克逊短革鲀, 杰克逊短革单棘鲀,
Synonymes
Aleuterius baueri (Richardson, 1846)
Aleuterius trossulus (Richardson, 1846)
Balistes jacksonianus (Quoy & Gaimard, 1824)
Balistes lamouroux (Quoy & Gaimard, 1824)
Brachaluteres baueri (Richardson, 1846)
Brachaluteres fidens (Whitley, 1931)
Brachaluteres trossulus (Richardson, 1846)
Brachaluteres wolfei (Scott, 1969)
Monacanthus distortus (Castelnau, 1873)
Monacanthus oculatus (Günther, 1870)
---------------------------
Description
Dorsal spines (total): 1; Dorsal soft rays (total): 24-29 (usually: 26-28); Anal soft rays: 22-28 (usually: 24-25); Pectoral fin rays: 10-12 (usually: 11); Caudal fin rays: 12; Vertebrae: 20. Head length: 2.4-3.2, body depth: 1.1-1.5, snout length: 3.9-4.9, and length of soft dorsal fin base: 2.1-2.7, all in SL; Eye diameter: 2.6-3.9, gill slit length: 4.1-7.8, first dorsal spine length: 1.0-2.7, interdorsal space: 1.1-1.9, longest soft dorsal ray (eight to twelth): 2.6-3.6, and caudal fin length: 0.9-1.4, all in head length; Caudal peduncle generally prominent, length: 2.2-4.8 in head length and 1.2-2.0 in caudal peduncle depth. Small fish with an almost circular body; Large expandable ventral flap (dewlap); Abdomen greatly inflatable; Skin covered in velvety spinules; First dorsal fin a single smooth spine that cannot be locked in an erect position; Anal fin and second dorsal fin opposite, both with unbranched rays. Max. length: 10.0 cm TL. Depth range: 1 - 73 m.
Color
Extremely variable. Usually green, brown or orange, but may also be yellow, pink, blue, purple, black, grey, or white; Head and body usually with black sometimes ocellated spots, spots increase in number and become smaller as the fish grows; Some individuals may lack spots, or may have short dashes forming lines on body; Dark stripes may also be present on the sides and head; Occasionally small white blotches form lines along the sides. Mature individuals have blue lines and spots usually following ventral profile of the head and body, a dark circular blotch is usually present on side just behind pectoral fin. Fins are greenish, although some mature individuals have a brilliant blue spots on the caudal fin.
Etymology
Brachaluteres: from Latin, brachium = harm, fin + from Greek prefix, a- = privative + from Greek, luteria, luter, luteros = one who looses, deliverer. Aluterus or aluteres meaning not free or detached, referring to the pelvis that does not form a spiny project (as it does in triggerfish).
jacksonianus: named after Port Jackson (Sydney Harbour - Australia) + from Latin suffix, -ianus = pertaining to.
Original description: Balistes jacksonianus Quoy & Gaimard, 1824 - Type locality: Sydney, Port Jackson, New South Wales, Australia.
Distribution
Eastern Indian Ocean, western Pacific: southern half of Australia to Chesterfield Islands and New Caledonia.
Extremely variable. Usually green, brown or orange, but may also be yellow, pink, blue, purple, black, grey, or white; Head and body usually with black sometimes ocellated spots, spots increase in number and become smaller as the fish grows; Some individuals may lack spots, or may have short dashes forming lines on body; Dark stripes may also be present on the sides and head; Occasionally small white blotches form lines along the sides. Mature individuals have blue lines and spots usually following ventral profile of the head and body, a dark circular blotch is usually present on side just behind pectoral fin. Fins are greenish, although some mature individuals have a brilliant blue spots on the caudal fin.
Etymology
Brachaluteres: from Latin, brachium = harm, fin + from Greek prefix, a- = privative + from Greek, luteria, luter, luteros = one who looses, deliverer. Aluterus or aluteres meaning not free or detached, referring to the pelvis that does not form a spiny project (as it does in triggerfish).
jacksonianus: named after Port Jackson (Sydney Harbour - Australia) + from Latin suffix, -ianus = pertaining to.
Original description: Balistes jacksonianus Quoy & Gaimard, 1824 - Type locality: Sydney, Port Jackson, New South Wales, Australia.
Distribution
Eastern Indian Ocean, western Pacific: southern half of Australia to Chesterfield Islands and New Caledonia.
Biology
This fish lack a small second dorsal-fin spine and, as a result, are unable to lock the first dorsal-fin spine in an upright position. They are poor swimmers, are very well-camouflaged and usually occur on sheltered reefs, amongst seagrasses or around jetties and piers. They are also able to greatly inflate their abdomens when threatened, thus increasing their body size. Omnivore.
Kawase (2005) studied the spawning behaviour of the Southern Pygmy Leatherjacket. He observed pre-spawning females repeatedly thrusting their snouts into the substrate where they would spawn, while the males exhibited courtship display and nuzzled the female’s face. The females and males then touched their abdomens in pairs and released gametes. Males reach sexual maturity at < 4.0 cm TL and females at < 3.0 cm TL. Fertilized eggs measure 0.74 mm in diameter and each clutch contains 50-191 eggs. Females may attach their eggs of algae found on the surface of seagrass leaves and other substrata.
Similar species
Brachaluteres fahaqa (Clark & Gohar, 1953) - Reported from Northern Red Sea endemic.
Brachaluteres taylori (Woods, 1966) - Reported from New Caledonia. Differs from other species in the genus in lacking a small second dorsal-fin spine. It also lack the fine dark lines of Brachaluteres taylori - dark lines, if present in Brachaluteres jacksonianus, are much wider and more stripe-like.
Brachaluteres ulvarum (Jordan & Fowler, 1902) - Reported from Northwestern Pacific: southern Korea and Japan.
This fish lack a small second dorsal-fin spine and, as a result, are unable to lock the first dorsal-fin spine in an upright position. They are poor swimmers, are very well-camouflaged and usually occur on sheltered reefs, amongst seagrasses or around jetties and piers. They are also able to greatly inflate their abdomens when threatened, thus increasing their body size. Omnivore.
Kawase (2005) studied the spawning behaviour of the Southern Pygmy Leatherjacket. He observed pre-spawning females repeatedly thrusting their snouts into the substrate where they would spawn, while the males exhibited courtship display and nuzzled the female’s face. The females and males then touched their abdomens in pairs and released gametes. Males reach sexual maturity at < 4.0 cm TL and females at < 3.0 cm TL. Fertilized eggs measure 0.74 mm in diameter and each clutch contains 50-191 eggs. Females may attach their eggs of algae found on the surface of seagrass leaves and other substrata.
Similar species
Brachaluteres fahaqa (Clark & Gohar, 1953) - Reported from Northern Red Sea endemic.
Brachaluteres taylori (Woods, 1966) - Reported from New Caledonia. Differs from other species in the genus in lacking a small second dorsal-fin spine. It also lack the fine dark lines of Brachaluteres taylori - dark lines, if present in Brachaluteres jacksonianus, are much wider and more stripe-like.
Brachaluteres ulvarum (Jordan & Fowler, 1902) - Reported from Northwestern Pacific: southern Korea and Japan.
Last update: 5, May 2024