Phil Garner, Southern California Marine Life, USA
Info
Boreoberthella chacei (J. Q. Burch, 1944)
Although Boreoberthella chacei looks like a slug, it has a thin, white inner shell (easier to feel than see) that extends at least half its body length. It has a single (protruding) gill on the right side of the body between the edge of the mantle and the foot. The rhinophores are rolled. The color is white, cream or orange with opaque white spots and often a thin white line around the edge of the back.
This unusual but striking species probably eats sea squirts and possibly sponges. Little is known about this species. Some members of this family can ward off predators with extremely strong acid secretions from their glands in their backs.
The White Berthella Boreoberthella chacei lays its eggs in a rolled-up ribbon attached to one edge of the substrate. The egg band is white, about 1 cm wide and 1 mm thick. The egg capsules in the band are oval, about 1.6 to 1.7 mm wide and contain 1–2 eggs each. At 11–12 °C the veliger larvae hatched within 19 days. Their developmental pattern is more similar to that of nudibranchs than to that of other studied flank gills (family Pleurobranchidae). The snail-like shell of the larva only becomes bilaterally symmetrical late in development. As the larvae burrow and metamorphose into the adult form, rapid expansion of the mantle over the shell occurs so that the shell merges into the interior. They also lose the large larval velar lobes and begin to form rhinophores and oral veils. The larvae also appear to have an ospradium (chemosensory organ), which is no longer present in adults.
Possibility of confusion: Boreoberthella chacei and Boreoberthella californica both occur in the same distribution area off the west coast of the USA in the Eastern Pacific and were temporarily thought to be two color variants of the same species. The molecular and morphological data obtained in a study showed that both represent two separate species.
Therefore, Boreoberthella californica (type locality: San Pedro, California) was retained for the southern morphotype, and Boreoberthella chacei (J. Q. Burch, 1944) (type locality: Crescent City, California) was revived for the northern morphotype.
Synonymised names
Berthella chacei (J. Q. Burch, 1944) · unaccepted > superseded combination
Pleurobranchus californicus denticulatus MacFarland, 1966 · unaccepted
Pleurobranchus chacei J. Q. Burch, 1944 · unaccepted (original combination)
Although Boreoberthella chacei looks like a slug, it has a thin, white inner shell (easier to feel than see) that extends at least half its body length. It has a single (protruding) gill on the right side of the body between the edge of the mantle and the foot. The rhinophores are rolled. The color is white, cream or orange with opaque white spots and often a thin white line around the edge of the back.
This unusual but striking species probably eats sea squirts and possibly sponges. Little is known about this species. Some members of this family can ward off predators with extremely strong acid secretions from their glands in their backs.
The White Berthella Boreoberthella chacei lays its eggs in a rolled-up ribbon attached to one edge of the substrate. The egg band is white, about 1 cm wide and 1 mm thick. The egg capsules in the band are oval, about 1.6 to 1.7 mm wide and contain 1–2 eggs each. At 11–12 °C the veliger larvae hatched within 19 days. Their developmental pattern is more similar to that of nudibranchs than to that of other studied flank gills (family Pleurobranchidae). The snail-like shell of the larva only becomes bilaterally symmetrical late in development. As the larvae burrow and metamorphose into the adult form, rapid expansion of the mantle over the shell occurs so that the shell merges into the interior. They also lose the large larval velar lobes and begin to form rhinophores and oral veils. The larvae also appear to have an ospradium (chemosensory organ), which is no longer present in adults.
Possibility of confusion: Boreoberthella chacei and Boreoberthella californica both occur in the same distribution area off the west coast of the USA in the Eastern Pacific and were temporarily thought to be two color variants of the same species. The molecular and morphological data obtained in a study showed that both represent two separate species.
Therefore, Boreoberthella californica (type locality: San Pedro, California) was retained for the southern morphotype, and Boreoberthella chacei (J. Q. Burch, 1944) (type locality: Crescent City, California) was revived for the northern morphotype.
Synonymised names
Berthella chacei (J. Q. Burch, 1944) · unaccepted > superseded combination
Pleurobranchus californicus denticulatus MacFarland, 1966 · unaccepted
Pleurobranchus chacei J. Q. Burch, 1944 · unaccepted (original combination)
