Heine Jensen, Norwegen
Info
Dendronotus lacteus (W. Thompson, 1840)
Dendronotus lacteus is a large species with a narrow body that can vary widely in color but is often white or light. This makes it difficult to distinguish them from closely related species. The tree snail lives in shallow water, often in kelp forests. The species lives in shallow water at low tide and to depths of several hundred meters, but is most commonly found from depths of 5 to 20 meters in the algae belt and kelp forest. Like closely related species, it eats hydrozoans and is found on a number of different hydrozoan species.
Dendronotus lacteus is large and elongated with a narrow body that can grow up to 160 mm long. Above the mouth it has a mouth veil with 4-10 appendages. The rinophores sit in a rinophore sheath that has 4-6 branched outgrowths on the edge, with the front and back outgrowths being slightly longer than those on the sides. The rinophores are laminated with 10-14 lamellae. The body has up to 4-8 pairs of gills along the edge on each side, the gills are often curled. The gills have a long stalk, they are branched, and some of these branches are in turn branched with short and blunt branches.
The body often has a uniform milky-white, dull base color, with thick skin that is not translucent. Gills and rhinophores are similar in color. There are also reddish-brown to brown specimens, sometimes with mottled pigmentation, often with small brownish spots.
Three Dendronotus species, all distributed along the Norwegian coast, have external morphological features that overlap. Dendronotus frondosus, Dendronotus lacteus and Dendronotus europaeus. The external signs typically used for identification are so similar that even slug experts have difficulty distinguishing species in the sea and from pictures with certainty.
Dendronotus phrondosus does not grow larger than 50 mm, while both Dendronotus lacteus and Dendronotus europaeus can grow to at least twice that size. In Dendronotus europaeus the second and third branches on the gills are long and pointed, the species looks bushier. The large Dendronotus lacteus is mainly light in color with opaque skin, as well as short and blunt branches on the gills. Dendronotus frondosus most commonly has brown mottled pigmentation and translucent skin. Although there are optical differences, a reliable determination is only possible through DNA analysis.
Etymology: The genus name Dendronotus comes from Greek, where dendros means trees and notus means back. The species name "lacteus" comes from Latin and means milky or milky white, which refers to the color of the often typical-looking form.
Synonymised names:
Dendronotus arborescens var. aurantiaca Friele, 1879 · unaccepted (dubious synonym)
Dendronotus luteolus Lafont, 1871 · unaccepted (dubious synonym)
Tritonia lactea W. Thompson, 1840 · unaccepted (original combination)
Dendronotus lacteus is a large species with a narrow body that can vary widely in color but is often white or light. This makes it difficult to distinguish them from closely related species. The tree snail lives in shallow water, often in kelp forests. The species lives in shallow water at low tide and to depths of several hundred meters, but is most commonly found from depths of 5 to 20 meters in the algae belt and kelp forest. Like closely related species, it eats hydrozoans and is found on a number of different hydrozoan species.
Dendronotus lacteus is large and elongated with a narrow body that can grow up to 160 mm long. Above the mouth it has a mouth veil with 4-10 appendages. The rinophores sit in a rinophore sheath that has 4-6 branched outgrowths on the edge, with the front and back outgrowths being slightly longer than those on the sides. The rinophores are laminated with 10-14 lamellae. The body has up to 4-8 pairs of gills along the edge on each side, the gills are often curled. The gills have a long stalk, they are branched, and some of these branches are in turn branched with short and blunt branches.
The body often has a uniform milky-white, dull base color, with thick skin that is not translucent. Gills and rhinophores are similar in color. There are also reddish-brown to brown specimens, sometimes with mottled pigmentation, often with small brownish spots.
Three Dendronotus species, all distributed along the Norwegian coast, have external morphological features that overlap. Dendronotus frondosus, Dendronotus lacteus and Dendronotus europaeus. The external signs typically used for identification are so similar that even slug experts have difficulty distinguishing species in the sea and from pictures with certainty.
Dendronotus phrondosus does not grow larger than 50 mm, while both Dendronotus lacteus and Dendronotus europaeus can grow to at least twice that size. In Dendronotus europaeus the second and third branches on the gills are long and pointed, the species looks bushier. The large Dendronotus lacteus is mainly light in color with opaque skin, as well as short and blunt branches on the gills. Dendronotus frondosus most commonly has brown mottled pigmentation and translucent skin. Although there are optical differences, a reliable determination is only possible through DNA analysis.
Etymology: The genus name Dendronotus comes from Greek, where dendros means trees and notus means back. The species name "lacteus" comes from Latin and means milky or milky white, which refers to the color of the often typical-looking form.
Synonymised names:
Dendronotus arborescens var. aurantiaca Friele, 1879 · unaccepted (dubious synonym)
Dendronotus luteolus Lafont, 1871 · unaccepted (dubious synonym)
Tritonia lactea W. Thompson, 1840 · unaccepted (original combination)
