Limax bielzii
| Limax bielzii | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Limax bielzii | ||||||||||||
| Seibert , 1873 |
Limax bielzii (also incorrectly spelled bielzi ) is a nudibranch species from the family of snails (Limacidae), which belongs to the subordination of land snails (Stylommatophora).
features
Limax bielzii is stretched out to over 20 cm long. The body is slim and pointed backwards. The coat takes about the length of the body, is rounded at the front and drawn out to a small blunt point at the back. The body is colored light brown, ocher yellow to vermilion, with the coat being a little more intense than the back. The side parts of the body get lighter from top to bottom, towards the soles of the feet. The keel is limited to the rear half of the back behind the mantle shield. It has the same color as the back, and is less often colored differently. In such specimens, the center line can extend to the rear edge of the coat. In these specimens, the red center line can be lined darker on both sides and there may be a slightly darker side band. The edge of the foot is blackish in color, the sole of the foot is divided into three parts, with the middle field being light, the side fields mostly darker. The sole can also be colored in a uniformly light color. The head and antennae, on the other hand, are blackish in color. There are about 25 skin furrows between the midline and the breathing hole. The breathing hole is outlined in black. The comparatively thin mucus on the sole of the foot is colorless, the body mucus is red in the red morph, and yellowish in the light brown morph.
In the genital apparatus, the penis is about half the length of the body; it is strongly twisted and cylindrical. The retractor starts at the apex of the penis, and the spermatic duct also ends there. The spermoviduct is thin, long and whitish. The spermatic duct is also quite long and connected to the penis over its entire length by a membrane. The spermathec is egg-shaped with a short stem. The free fallopian tube is expanded in the shape of a cylinder in the front section. The atrium is greatly reduced and quite small.
The bowl plate is somewhat irregularly oval shaped. The nucleus is raised, lies almost at the lower edge, shifted slightly to the left. There are clear streaks of growth on the top.
Similar species
Limax bielzii is very similar in anatomy to the Black Schnegel ( Limax cinereoniger ). Only the penis of Limax bielzii is slightly shorter and thinner than the penis of Limax cinereoniger . The animals are colored light brown to vermilion, in contrast to mostly gray-black colors and a mostly existing drawing in Limax cinereoniger . Gerhardt (1935) describes two color morphs of L. bielzii , a light brown morph and a vermilion morph without color transitions.
Geographical distribution and habitat
The species seems to be very rare. Evidence is so far only available from Lower Austria , northern Styria , the Pieniny Mountains (Poland) and from the Moravian Beskids (Czech Republic).
Limax bielzii lives in moderately moist mixed deciduous forests on limestone soil.
Way of life
The species is nocturnal. Little is known about nutrition in the natural biotope. In captivity, they were fed fresh plant material.
The species barrier is maintained in the representatives of the Schnegel by an often very complex copulation ritual that often lasts for hours, while the anatomy is often surprisingly similar. The mating ritual of Limax bielzii has been very well examined and documented by Ulrich Gerhardt under laboratory conditions. Usually a specimen ready to mate finds another specimen ready to mate by following its slime trail. Once the two specimens have met, a persecution often lasts for over an hour and the persecutor repeatedly licks the tail tip of the persecuted person. On a vertical wall, approx. 70 cm above the floor, the pursued animal bent its head back to the right behind. The pursuer stopped in a stretched position, and the pursued animal began to lick its head. Then the front body wrapped itself around each other, with the respective soles of the feet remaining attached to the base for about half (the length). The front bodies were rotated so that when the heads were crossed, the genital pores came to lie next to each other and pointed downwards. Then the penes emerged from the genital orifices, already twisted somewhat in a spiral, over a length of 2 cm at a distance of about 4 mm from each other. Already at this length they looked for each other and turned around at this length. Only then were they everted to their full length, they wrapped around each other quite tightly and helically. The base of this structure is white, a following larger piece is dark bluish, the last third is whitish again. After the penes have been fully everted, the so-called combs are erected, which widen and rotate like a shovel towards the tip of the penis. Even in this phase, the sperm packets slide down the penis to the tip. Now the sperm packets are transferred. As the penes continue to rotate, the combs close around the other partner's penis and transfer the sperm mass to the other partner's penis. After that, the partners are drawn in and separated. Just two minutes after the sperm transfer, the two partners were separated again. The penes were not completely withdrawn, but hung up to a length of four centimeters from the genital opening. Again after only about two minutes they were completely withdrawn. The actual copulation thus took less than 10 minutes, compared to around 20 minutes for the Black Schnegel ( Limax cinereoniger ), i.e. only half as long. The foreplay is also different with the Black Schnegel, the drawing in of the penes is slower.
The eggs are laid in August, up to 95 pieces were counted in a clutch, which are mostly loose, rarely strung in strings. The shape varies from spherical to elliptical and oval. The size varies widely, ranging in diameter from around 4 mm to 9 mm. The young hatch after about four weeks and are then 22 to 24 mm long (stretched out). They are pale, with a reddish tone, and translucent. The bowl in the coat shimmers through. After about a month the animals become more reddish-gray and have a blackish longitudinal band on the sides; the coat becomes darker. The animals are about two years old.
Taxonomy
The taxon was first scientifically described by Hermann Seibert in 1873 as Limax Bielzii . The type material came from near "Mistek" (today Frýdek-Místek , Czech Republic). The systematic position was somewhat controversial in the past, as some authors do not recognize the taxon as an independent species, but instead viewed it as a subspecies of the black snail ( Limax cinereoniger ). However, there are clear differences in behavior (mating ritual) and minor differences in anatomy, which clearly speak for a species status. The incorrect spelling bielzi can also be found in some publications .
supporting documents
literature
- Gerhardt, Ulrich 1935: Further investigations into the copulation of the slugs. Journal for Morphology and Ecology of Animals, 30: 297–332, Berlin.
- Kerney, Michael P., RAD Cameron & Jürgen H. Jungbluth 1983: The land snails of Northern and Central Europe. 384 pp., Paul Parey, Hamburg & Berlin 1983 ISBN 3-490-17918-8 .
- Wiktor, Andrzej 1973: The Polish Nudibranchs. 182 p., Monograph Fauny Polski, Polska Akademia Nauk Zakład Zoologii Systematycznej i Doświadczalnej, Warsaw & Kraków.
Individual evidence
- ↑ a b Gerhardt (1935: pp. 301–306) (there written bielzi )
- ↑ a b Wiktor (1973: pp. 72–74) (there written bielzi )
- ↑ Seibert, Hermann 1873: To the knowledge of our nudibranchs. Malakozoologische Blätter, 21: 190-203, Cassel / Kassel Online at archive.org .
- ↑ Kerney et al. (1983: pp. 184, 190) (there written bielzi )