Arion transylvanus
| Arion transylvanus | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Arion transylvanus | ||||||||||||
| Simroth , 1885 |
Arion Transsylvanus is a slug species from the family of slugs (Arionidae) within the order of snails (Pulmonata). The taxon originally described as a varietywas only recognized as a separate species in 2010.
features
The medium-sized animals are stretched out 40 to 70 mm long. The basic color varies greatly within a population and also between different populations from intense yellow-orange, through various shades of brown to deep or dark brown. There are often bandages on the side, but they can extinguish a great deal or, more rarely, be completely absent. There is often a slightly lighter stripe at the top of the side bandages. The back between the side ties is usually darker than the area between the side ties and the edge of the foot. Often there is a lighter back stripe on the back. The sole of the foot is always cream-colored. The body mucus can be colorless to yellow-orange in color.
In the genital system, the flattened, egg-shaped sex gland is of medium size. It sits on the edge of the midgut gland and is therefore visible when the mantle is opened. The color of the sex gland varies from reddish brown to purple gray. The fallopian tube is tubular with a constant thickness, or with a short part at the end that narrows slightly. The ligula in the vagina is poorly developed and consists of two weak longitudinal ridges. The retractor muscle attaches to the stem of the seminal vesicle (spermathec) and to the free fallopian tube. The seminal vesicle conductor ("stem") is approximately the same length as the seminal vesicle itself. This is round to elliptical. The peduncle of the seminal vesicle and the epiphallus closely approach each other up to the confluence with the atrium. The transition from the vas deferens to the epiphallus is usually clearly marked. The epiphallus is significantly wider, has thicker walls and is more twisted than the thin and straight vas deferens. The epiphallus is about as long as the vas deferens. In the dorsal view, the mouths of the epiphallus, the stalk of the seminal vesicle and the fallopian tube in the atrium are aligned; the epiphallus on the left, the stalk of the seminal vesicle in the middle, and the fallopian tube on the right.
Similar species
The species is very similar to the brown slug ( Arion fuscus ), based on purely external characteristics it cannot be differentiated from A. fuscus . In the genital system, the flattened-elliptical sex gland is always clearly visible at the edge of the midgut gland (after opening the mantle). In the brown slug, the plump sex gland is embedded in the midgut gland and is not visible after opening the mantle. In Arion transsylvanus , the sex gland is larger and lighter than the sex gland of the brown slug. The differences between the light brown slug ( Arion subfuscus ) and Arion transsylvanus are less clear. The sex gland of Arion subfuscus is larger and lighter (yellowish, light gray to light purple in color). In both species it lies on the edge of the midgut gland and is visible when the mantle is open. As far as is known, the areas of the two species are mutually exclusive.
Geographical distribution and habitat
Arion transsylvanus is widespread in Transylvania (Romania), formerly also known as Transylvania. The area stretches to eastern Poland . Overall, however, the actual distribution is unknown, as the species has so far not been distinguished from the Arion fuscus / subfuscus complex. Animals collected in other regions of the Carpathian Mountains , e.g. B. in the Tatra Mountains or in southern Poland, belonged to Arion fuscus . Heinrich Simroth found the species (at that time still referred to as a variety) at 2300 m on Mount Negoi. Alexandru Grossu (1970) even found it at an altitude of 2500 m above sea level.
Taxonomy and nomenclature
The taxon was first described in 1885 by Heinrich Simroth as Arion subfuscus var. Transsylvanus . Kurt Jordaens and others upgraded the taxon to an independent species in 2010.
supporting documents
literature
- Heinrich Simroth 1885: Attempt at a natural history of the German nudibranch and their European relatives. Journal for Scientific Zoology, 42: pp. 203–366 Online at archive.org (p. 284)
- Kurt Jordaens, Jan Pinceel, Natalie Van Houtte, K. Breugelmans & Thierry Backeljau 2010: Arion transsylvanus (Mollusca, Pulmonata, Arionidae): rediscovery of a cryptic species. Zoologica Scripta, 39: pp. 343-362 doi : 10.1111 / j.1463-6409.2010.00425.x
Individual evidence
- ↑ Alexandru V. Grossu: Revizuirea speciilor genului Arion Férussac din Romania (Gastropoda, Arionidae). Comunicari de Zoologie, 1970: 61-74, 1970.