Conus planorbis
| Conus planorbis | ||||||||||||
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Housing of Conus planorbis |
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| Scientific name | ||||||||||||
| Conus planorbis | ||||||||||||
| Born , 1778 |
Conus planorbis is the species name of a screw from the family of the cone snails (genus Conus ), which in Indopazifik is used and from Vielborstern , particularly Eunicidae fed. According to Röckel, Korn and Kohn, Conus vitulinus is just one form of this species.
features
Conus planorbis bears a medium-sized to moderately large, moderately firm to firm snail shell , which in adult snails reaches 4 to 8 cm in length. The vitulinus form is a little heavier, but very variable in weight. The circumference of the body is conical or bulbous, the contour in the quarter at the shoulder is convex and otherwise straight. The shoulder is angled. The thread is low, its outline is slightly concave, S-shaped or convex. The Protoconch has about three whorls and measures a maximum of 0.8 mm. The seam ramps of the Teleoconch are flat, often concave in the later passages, with spiral grooves increasing from 1 to 5 to 7, but this sculpting often becomes weak on the last two passages. The third or quarter of the body is provided with alternating raised and grainy ribs, spiraling at alternating intervals, but usually more dense towards the base, sometimes also with weak ribs towards the shoulder, but the sculpting disappears with large individuals.
The basic color of the housing is white in the typical shape, sometimes undercolored with cream or dark yellow on the body, but rarely on the seam ramps. The circumference of the body is covered on both sides of the middle with a wide yellowish to dark brown spiral band, which sometimes mixes color with the neighboring surfaces, but usually leaves a band in the basic color free in the middle and on the shoulder, the band on the shoulder can be very narrow and littered with brown axial markings.
In the Vitulinus form , the basic color of the housing is white, as in the typical form, but the area around the body is covered on both sides of the center with a wide, dark yellow to dark brown spiral band, both either continuous or reduced and split into axial stripes and flames. Dark brown axial stripes or flames cross the brown bands as well as those in the basic color, the latter varying in width and being drawn sparsely to densely with dark brown axial markings.
Both color forms - the typical and vitulinus - appear sympatric in numerous places and merge into one another. In both forms and their transitions, dotted, dashed or solid brown to dark brown spiral lines lying on top of each other can extend from the base to the shoulder and vary in their number and density.
The base and the siphonal fasciole are purple and often darkened by an overlying dark brown color. The apex is cream colored. The late suture ramps have alternating numerous brown radial markings, which in the form of vitulinus and in intermediate forms often extend to the shoulder area. The inside of the case mouth is white, at the base purple to brown.
The thin and translucent to thick and almost opaque periostracum is gray, yellow or brown. It has tufted spiral lines on the body and the seam ramps, and a slightly longer hem on the shoulder.
The snail itself is yellow, the upper side of the foot lighter in the middle, sometimes with white dots on the sides and front, the edge areas are spotted with brown to black markings, which can flow together at the front, but can also be missing at the back. The sole of the foot is dark yellow with pale spots and sparse brown spots. The rostrum is dark yellow, the proboscis a little paler. The sipho is pale yellow with a dark yellow edge and a blackish-brown ring for a third or half of the length from the tip.
The small radula teeth connected to a poison gland have been examined in the form of vitulinus . They have a barb on the tip and a second barb on the opposite side. They are sawn by a double row of protruding teeth over the length of the second barb or up to twice this length. There is a distinct spur at the base.
distribution and habitat
Conus planorbis is widespread in the central and western Pacific Ocean including Hawaii , but probably also in the Indian Ocean in the Mascarene Islands and Seychelles . It lives in the intertidal zone and down to a depth of around 60 m on reef rocks under dead corals, on sandy surfaces with algae growth, on corals and boulders. Both forms ( planorbis and vitulinus ) occur sympatric.
Development cycle
Like all cone snails, Conus planorbis is sexually separated and the male mates with the female with his penis . The female lays egg capsules about 23 mm long and 16 to 17 mm wide on common basal plates on the underside of rocks. The eggs inside have a diameter of around 225 µm, from which it is concluded that the Veliger larvae swim freely for at least 21 days before they sink down and metamorphose into crawling snails .
nutrition
On the coast of Hawaii in the form eats vitulinus of Conus planorbis errante polychaete family Eunicidae they with their Radulazähnen stands and with the help of the poison from the venom gland immobilized.
Taxonomy and status of Conus planorbis and Conus vitulinus
Conus planorbis was first described by Ignaz von Born in 1778 , while Conus vitulinus by Christian Hee Hwass in the Encyclopédie méthodique - Histoire naturelle des vers by Jean-Guillaume Bruguière in 1792. Both appear sympathetic . According to Dieter Röckel, Werner Korn and Alan J. Kohn (1995), the latter is not a separate species and not a subspecies, but merely a color form of Conus planorbis .
literature
- George Washington Tryon: Manual of Conchology, structural and systematic, with illustrations of the species , vol. VI; Academy of Natural Sciences, Philadelphia 1884. C [onus] planorbis Born., P. 50, C [onus] vitulinus Linn., P. 51.
- Jerry G. Walls: Cone Shells: A Synopsis of the Living Conidae TFH Publications, Neptune (New Jersey) 1979. p. 804.
- Dieter Röckel, Werner Korn, Alan J. Kohn: Manual of the Living Conidae Vol. 1: Indo-Pacific Region . Verlag Christa Hemmen, Wiesbaden 1995. The texts on the individual cone snail species of the Indo-Pacific are published on The Conus Biodiversity website with the permission of the authors (see web links).
Web links
- The Conus Biodiversity Website: Conus planorbis Born, 1778
- Dieter Röckel: The Conidae family. Conus planorbis Born, 1789 Conus vitulinus Hwass in Brugière, 1792
- Underwater Kwajalein: Conus planorbis Born, 1778 , Underwater Kwajalein: Conus vitulinus Hwass in Brugière, 1792
Individual evidence
- ^ Alan J. Kohn (1959): The Ecology of Conus in Hawaii. Ecological Monographs 29 (1), pp. 47-90.