Rafi Amar, Israel
Info
Hexabranchus lacer (Cuvier, 1804)
Currently there are 6 scientifically described species of Hexabranchus and a lot of confusion on the internet and other media:
Species Hexabranchus aureomarginatus Ostergaard, 1955
Species Hexabranchus giganteus Tibiriçá, Pola & Cervera, 2023
Species Hexabranchus lacer (Cuvier, 1804)
Species Hexabranchus morsomus Ev. Marcus & He Marcus, 1962
Species Hexabranchus sandwichensis Gray, 1850
Species Hexabranchus sanguineus (Rüppell & Leuckart, 1830)
Hexabranchus lacer reaches a size of up to 22cm (according to unconfirmed reports up to 50cm in the Marshall Islands). The notum in resting adults is broad and irregularly covered with pustules. The body is pear-shaped when the mantle is curled and oval when stretched out. The mantle extension gradually widens towards the rear, but is short and differentiated on the head.
Hexabranchus lacer is a common, widespread species and very variable. There are different morphs in all stages of life, which differ in some external details. Back strapping details vary with white border straps, red border straps, side stripes, red strap breaks and purple tint blending together. The innermost dorsal band of adult animals is sharply bordered in the middle and strongly jagged. Diffuse white pigment is often present on and around the rhinophore sheath (most prominent in larger animals), and the rhinophore lamellae are usually outlined in white. The general color pattern of adults is "blotchy".
The rhinophore sheath is short and smooth-edged. The rhinophire stalk is stocky and the club is broader than in Hexabranchus sanguineus. The rhinophores of adult animals have about 40-50 lamellae. The gill branches are complex and multiply pinnate, with a variable number of gill tufts (often more than seven) forming a circle around the anus. The anus is elevated on a tubular papilla. The mouth tentacles are large, fleshy, oval, elongated, and notched. The foot is narrower than the body.
This species is often nocturnal. Whether they are diurnal or nocturnal seems to depend on the habitat. Younger and medium-sized specimens are often found in tidal pools, adult larger specimens usually in about 5m depth. The preferred habitat is coral reefs.
Comparison/differences to Hexabranchus aureomarginatus:
Compared to the Hexabranchus aureomarginatus, the egg mass is usually taller, more tightly coiled, and darker in color. The gills of Hexabranchus lacer are typically held in a more recumbent position than Hexabranchus sanguineus. In the case of Hexabranchus lacer, the notum appears wide and irregularly slightly to heavily pustulated in large, resting animals. Nevertheless, the pustules largely "disappear" when swimming. Juveniles are commonly seen in tide pools and shallow water, while adults are found in moderately sheltered underwater habitats and on deeper reefs.
Synonymised names:
Aethedoris indica Abraham, 1877 · unaccepted
Doris flammulatus Quoy & Gaimard, 1832 · unaccepted
Doris gloriosa Kelaart, 1858 · unaccepted > superseded combination
Doris lacera Cuvier, 1804 · unaccepted > superseded combination (Declared nomen oblitum under Art....)
Doris marginata Quoy & Gaimard, 1832 · unaccepted (invalid; not Montagu, 1804)
Doris marginatus Quoy & Gaimard, 1832 · unaccepted
Doris sumptuosa Gould, 1852 · unaccepted
Doris superba Gould, 1852 · unaccepted
Heptabranchus burnettii A. Adams, 1848 · unaccepted
Hexabranchus adamsii Gray, 1850 · unaccepted
Hexabranchus anaiteus Bergh, 1878 · unaccepted
Hexabranchus faustus Bergh, 1878 · unaccepted
Hexabranchus gloriosus (Kelaart, 1858) · unaccepted > junior subjective synonym
Hexabranchus laciniatus [sic] · unaccepted (incorrect subsequent spelling of...)
Hexabranchus marginatus (Quoy & Gaimard, 1832) · unaccepted
Hexabranchus orbicularis Abraham, 1877 · unaccepted
Hexabranchus punctatus Bergh, 1905 · unaccepted > junior subjective synonym
Hexabranchus sumptuosa (Gould, 1852) · unaccepted
Hexabranchus superba (Gould, 1852) · unaccepted
Currently there are 6 scientifically described species of Hexabranchus and a lot of confusion on the internet and other media:
Species Hexabranchus aureomarginatus Ostergaard, 1955
Species Hexabranchus giganteus Tibiriçá, Pola & Cervera, 2023
Species Hexabranchus lacer (Cuvier, 1804)
Species Hexabranchus morsomus Ev. Marcus & He Marcus, 1962
Species Hexabranchus sandwichensis Gray, 1850
Species Hexabranchus sanguineus (Rüppell & Leuckart, 1830)
Hexabranchus lacer reaches a size of up to 22cm (according to unconfirmed reports up to 50cm in the Marshall Islands). The notum in resting adults is broad and irregularly covered with pustules. The body is pear-shaped when the mantle is curled and oval when stretched out. The mantle extension gradually widens towards the rear, but is short and differentiated on the head.
Hexabranchus lacer is a common, widespread species and very variable. There are different morphs in all stages of life, which differ in some external details. Back strapping details vary with white border straps, red border straps, side stripes, red strap breaks and purple tint blending together. The innermost dorsal band of adult animals is sharply bordered in the middle and strongly jagged. Diffuse white pigment is often present on and around the rhinophore sheath (most prominent in larger animals), and the rhinophore lamellae are usually outlined in white. The general color pattern of adults is "blotchy".
The rhinophore sheath is short and smooth-edged. The rhinophire stalk is stocky and the club is broader than in Hexabranchus sanguineus. The rhinophores of adult animals have about 40-50 lamellae. The gill branches are complex and multiply pinnate, with a variable number of gill tufts (often more than seven) forming a circle around the anus. The anus is elevated on a tubular papilla. The mouth tentacles are large, fleshy, oval, elongated, and notched. The foot is narrower than the body.
This species is often nocturnal. Whether they are diurnal or nocturnal seems to depend on the habitat. Younger and medium-sized specimens are often found in tidal pools, adult larger specimens usually in about 5m depth. The preferred habitat is coral reefs.
Comparison/differences to Hexabranchus aureomarginatus:
Compared to the Hexabranchus aureomarginatus, the egg mass is usually taller, more tightly coiled, and darker in color. The gills of Hexabranchus lacer are typically held in a more recumbent position than Hexabranchus sanguineus. In the case of Hexabranchus lacer, the notum appears wide and irregularly slightly to heavily pustulated in large, resting animals. Nevertheless, the pustules largely "disappear" when swimming. Juveniles are commonly seen in tide pools and shallow water, while adults are found in moderately sheltered underwater habitats and on deeper reefs.
Synonymised names:
Aethedoris indica Abraham, 1877 · unaccepted
Doris flammulatus Quoy & Gaimard, 1832 · unaccepted
Doris gloriosa Kelaart, 1858 · unaccepted > superseded combination
Doris lacera Cuvier, 1804 · unaccepted > superseded combination (Declared nomen oblitum under Art....)
Doris marginata Quoy & Gaimard, 1832 · unaccepted (invalid; not Montagu, 1804)
Doris marginatus Quoy & Gaimard, 1832 · unaccepted
Doris sumptuosa Gould, 1852 · unaccepted
Doris superba Gould, 1852 · unaccepted
Heptabranchus burnettii A. Adams, 1848 · unaccepted
Hexabranchus adamsii Gray, 1850 · unaccepted
Hexabranchus anaiteus Bergh, 1878 · unaccepted
Hexabranchus faustus Bergh, 1878 · unaccepted
Hexabranchus gloriosus (Kelaart, 1858) · unaccepted > junior subjective synonym
Hexabranchus laciniatus [sic] · unaccepted (incorrect subsequent spelling of...)
Hexabranchus marginatus (Quoy & Gaimard, 1832) · unaccepted
Hexabranchus orbicularis Abraham, 1877 · unaccepted
Hexabranchus punctatus Bergh, 1905 · unaccepted > junior subjective synonym
Hexabranchus sumptuosa (Gould, 1852) · unaccepted
Hexabranchus superba (Gould, 1852) · unaccepted
