The handfishes are a poorly known lophiiform family containing four described species in two genera: Brachionichthys and Sympterichthys. Handfishes are restricted to dispersed inshore marine habitats off southern Australia and primarily Tasmania. Like most other shallow-dwelling lophiiforms, they are exclusively benthic. Several species in the family are of conservation concern and listed as vulnerable to extinction by the Australian government (Last et al., 1983).
Australia's CSIRO has produced a QuickTime clip that outlines the conservation status of the spotted handfish (Brachionichthys hirsutus) and demonstrates the tetrapod-like locomotion of brachionichthyids.
Relationship of Brachionichthyidae to Other Antennarioidei
© 2005 Theodore W. Pietsch
The hypothesized relationships of the Antennarioidei as presented by Pietsch (1981) and Pietsch and Grobecker (1987). See below for character states.
The family Brachionichthyidae is classified as the basal sister taxon of a clade including the Lophichthyidae, Tetrabrachiidae, and Antennariidae; these four families forming the lophiiform suborder Antennarioidei (Pietsch, 1981; Pietsch and Grobecker, 1987). Monophyly of the suborder and the relationships within it are supported by a total of seven synapomorphies (see above cladogram):
- Posteromedial process of vomer emerging from ventral surface as a laterally compressed, keel-like structure, its ventral margin (as seen in lateral view) strongly convex;
- Postmaxillary process of premaxilla spatulate;
- Opercle similarly reduced in size;
- Ectopterygoid triradiate, a dorsal process overlapping the medial surface of metapterygoid;
- Proximal end of hypobranchials II and III deeply bifurcate;
- Interhyal with a medial, posterolaterally directed process that makes contact with the respective preopercle;
- Illicial pterygiophore and pterygiophore of third dorsal-fin spine with highly compressed, blade-like dorsal expansions.
Body deep; skin naked or covered with denticles. Second dorsal-spine joined to third by a membrane. Gill opening small, behind pectoral fin base. Dorsal-fin rays 15-18; anal-fin rays 7-10. Pelvic fin with one spine and 4 rays. A small illicium present just above mouth, function of which is unknown but does not appear to be used in luring potential prey. Attains 15 cm. Benthic, occurring in inshore waters at depths up to 60 m.
Life History and Behavior
Reproduction and Early Life History
Information on the reproduction of handfishes comes largely from monitoring programs of endangered or threatened species (Bruce et al., 1997; 1999). The spotted handfish (B. hirsutus) and red handfish (B. politus) spawn during September and October (Last and Bruce, 1997). Spawning in captivity is preceded by displays between male and female consisting of a variety of fin and body movements. Fertilization is external. It is not known if a single or multiple males fertilize the eggs of individual females in the wild. Egg masses of 80-250 eggs are spawned on the bottom around an isolated semi-rigid vertical object. The spotted handfish most commonly attach their eggs masses to stalked sea squirts (Sycozoa sp.); red handfish utilize algae (Caulerpa sp.). Handfish eggs are large (approximately 3–4 mm in diameter), orange in color, housed in individual flask-shaped envelopes, and interconnected in a single mass by a series of fine tubules and tendrils.
The female remains with the egg mass for seven to eight weeks until hatching. In captivity, females continue to feed during this period and have been observed probing the egg mass with their illicium and occasionally grasping the egg mass with their mouth.
Handfishes lack a pelagic larval stage, hatching fully formed juveniles (6–7 mm SL) that fall directly to the sea floor and remain near the spawning site.
Spotted handfish hatch in November and grow rapidly to 35–50 mm SL by the first year, and to 70–80 mm SL the second year. After two years the growth rate slows to only a few millimeters annually. Females reach maturity after 2-3 years at a size of 75–80 mm SL; male size at maturity remains unknown, however, the smallest observed captive-spawning male was 87 mm TL.
Evolution and Systematics
Molecular Biology and Genetics
Statistics of barcoding coverage
Specimens with Sequences:19
Specimens with Barcodes:19
Species With Barcodes:5
A handfish is an anglerfish of the family Brachionichthyidae, a group which comprises five genera and 14 extant species. These benthic marine fish are unusual in the way they propel themselves by walking on the sea floor rather than swimming.
Handfish grow up to 15 cm (5.9 in) long, and have skin covered with denticles (tooth-like scales), giving them the alternate name warty anglers. They are slow-moving fish that prefer to 'walk' rather than swim, using their modified pectoral fins to move about on the sea floor. These highly modified fins have the appearance of hands, hence their scientific name, from Latin bracchium meaning "arm" and Greek ichthys meaning "fish".
Like other anglerfish, they possess an illicium, a modified dorsal fin ray above the mouth, but it is short and does not appear to be used as a fishing lure.[dubious ] The second dorsal spine is joined to the third by a flap of skin, making a crest.
- Sepkoski, Jack (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology 364: 560.
- Last, P.R.; Gledhill, D.C. (2009). "A revision of the Australian handfishes (Lophiiformes: Brachionichthyidae), with descriptions of three new genera and nine new species". Zootaxa 2252: 1–77.
- Pietsch, Theodore W. (2005). "Brachionichthyidae". Tree of Life web project. Retrieved 4 April 2006.
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