Dendronotus
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| Dendronotidae | ||||||||||||
| Allman , 1845 | ||||||||||||
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| Dendronotus | ||||||||||||
| Alder & Hancock , 1845 |
Dendronotus is a genus and at the same time, as Dendronotidae, a monogeneric family of sapling snails in the subordination of nudibranchs . The small to large, exclusively marine caseless snails that live in the North Atlantic and North Pacific mainly eat hydrozoa and sea anemones .
features
The tree snails of the genus Dendronotus have an elongated, nudibranch- like body. They have a mouth sail with 2 to 5 pairs of finger-like, mostly forked appendages. The antennae above the head, the elongated and thickened rhinophores that can be retracted in antennae sheaths , have 8 to 30 transverse lamellae. The edges of the antennae sheaths are elongated into tree-like structures. The back is covered at its edges with 4 to 8 extensions of the mantle , which are also branched like trees. In young animals the same runners of the midgut gland are found , but unlike in the cerata of the thread snail, no nettle capsules are stored here, and in adults these runners are no longer present. The midgut gland consists of a large posterior and two small anterior lobes. The stomach has no chewing plates.
The rather narrow radula has central teeth with a large cusp and elongated pointed posterior teeth. The snails have a pair of strong jaws. The anus as well as the openings of the nephridia and the genital organs are on the right side of the snail.
Like other tree snails, the snails of the genus Dendronotus are hermaphrodites . They have an unreinforced penis and a hermaphroditic gland , which is located on the abdominal side below the midgut gland. The male and female genital openings are close to each other. The snails mate with each other and attach their long egg strings, in whose transparent shell you can see the numerous eggs, often on the cnidarians, which serve the snails as prey. Numerous Veliger larvae hatch from the eggs, feed on plankton and, after a long pelagic phase, metamorphose into small tree snails .
The tree snails of the genus Dendronotus eat various cnidarians, including sea anemones and hydrozoa , and to a lesser extent other prey. In addition to sea anemones, Dendronotus iris also eats cordworms .
Spread and some species
In European Atlantic waters the genus Dendronotus is represented by the up to 10 cm long shaggy tree snail ( Dendronotus frondosus ). The biodiversity is greater on the Pacific coast of North America, where smaller species such as the only up to 3.5 cm long Dendronotus albus live, but where Dendronotus iris can be up to 30 cm long.
Systematics
According to Bouchet and Rocroi (2005) the family Dendronotidae is one of nine families in the superfamily Tritonioidea , which in turn forms the suborder Dendronotida. The genus Dendronotus Alder & Hancock, 1845 is the only genus of the monogeneric family Dendronotidae. The two generic names Amphitrite Ascanius, 1774 and Pseudobornella Baba, 1932 are synonymous with Dendronotus .
The genus Dendronotus has 17 species:
- Dendronotus albopunctatus Robilliard, 1972
- Dendronotus albus MacFarland, 1966 (Synonym: D. diversicolor Robilliard, 1972)
- Dendronotus comteti Valdés & Bouchet, 2011
- Dendronotus dalli Bergh, 1879
- Dendronotus elegans A. E. Verril, 1880
- Dendronotus frondosus (Ascanius, 1774) (synonyms: D. arborescens , D. reynoldsi )
- Dendronotus gracilis Baba, 1949
- Dendronotus iris J.G. Cooper, 1863 (Synonyms: D. giganteus , D. nanus Marcus & Marcus, 1967)
- Dendronotus lacteus (Thompson W., 1840)
- Dendronotus noahi Pola & Stout, 2008
- Dendronotus orientalis (Baba, 1932)
- Dendronotus patricki Stout, NG Wilson & Valdés, 2011
- Dendronotus regius Pola & Stout, 2008
- Dendronotus robustus A. E. Verrill, 1870 (Synonym: D. velifer )
- Dendronotus rufus O'Donoghue, 1921
- Dendronotus subramosus MacFarland, 1966
- Dendronotus venustus MacFarland, 1966
literature
- Robert D. Beeman, Gary C. Williams: Opisthobranchia and Pulmonata , in: Robert Hugh Morris, Donald Putnam Abbott, Eugene Clinton Haderlie: Intertidal Invertebrates of California . Stanford University Press, 1st ed., Stanford (CA, USA) 1980, pp. 308-354. Dendronotus : p. 332f.
- Philippe Bouchet & Jean-Pierre Rocroi: Part 2. Working classification of the Gastropoda . Malacologia, 47: 239-283, Ann Arbor 2005 ISSN 0076-2997
Web links
Individual evidence
- ↑ Dave Cowles, Wallawalla.edu (2005): Dendronotus iris (Cooper, 1863) ( Memento of the original from September 28, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ A b World Register of Marine Species , Dendronotidae Allman, 1845 , Dendronotus Alder & Hancock, 1845
