Spiraxidae
| Spiraxidae | ||||||||||||
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Rosy Wolf Snail , Euglandina rosea (Férussac 1821) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Spiraxidae | ||||||||||||
| HB Baker , 1939 |
Spiraxidae is the name of a family of snails from the suborder land snails (Stylommatophora), which are common in Central America , South America and parts of North America . Only the five species of the genus Poiretia can be found in the Mediterranean area . They are predatory snails that mainly feed on other snails. There are about 260 described species in 18 genera.
features
The Spiraxidae have small to large, mostly egg-shaped to elongated egg-shaped housings. The radula teeth are one or two pointed. The foot is long and pointed at the back with a pronounced lower pit. They have a rather deep but thin coat collar and only small right, front, back and left coat lobes. The lung wall is elongated. The main vein is often bounded by muscle ligaments. The anal mantle gland, which is relatively large in small species, extends between the hindgut and ureter. The hermaphroditic gland (Ovotestis) is about a turn long and embedded in the midgut gland , about half a turn above the stomach. The gonoduct swells significantly when it is filled with semen . The prostate is completely separated from the uterus. The free vas deferens is quite heavy and muscular, or without enlargement. The penis has no appendages. The retractor is set high on the diaphragm and on or next to the tip of the penis. The atrial opening is under the base of the right eye feeler.
Occurrence and way of life
The Spiraxidae live in tropical and subtropical regions of North America, Central America including the Caribbean and South America from the southeast of the United States to Brazil and Peru , with by far the greatest biodiversity being found in Central America . The rosy wolf snail is also found as an invasive species in large parts of Oceania . The five species of the genus Poiretia in southern Europe and North Africa are an exception in the family in terms of distribution .
The Spiraxidae live predatory on other snails, among others. The prey is usually seized and devoured with the radula ; In this way, snails are pulled out of the barrel. On the other hand, snails of the genus Poiretia etch holes in the shell of their prey with acidic secretions from their feet.
Systematics
The taxon was proposed by Baker in 1939 as a subfamily Spiraxinae within the Oleacinidae family and was removed from the Oleacinidae as a separate family Spiraxidae in 1962 by the same author on the basis of anatomical features.
According to the revised taxonomy of Gastropoda according to Bouchet and Rocroi (2005), the Spiraxidae include the two subfamilies Spiraxinae HB Baker, 1939 and Micromeninae Schileyko, 2000.
According to the system of Thompson (2010), the family has 3 subfamilies. The Euglandininae, which previously belonged to the Oleacinidae, are now counted to the Spiraxidae. The Spiraxinae (Baker 1939) have small, thin, mostly translucent shells. The radula teeth are two-pointed. The shells of the Euglandininae (Baker 1941) are mostly medium to large and ovate to oblong ovoid. The radula teeth are single-pointed. The Streptostylinae (Baker 1941) have small to medium-sized, egg-shaped to elongated egg-shaped shells. The radula teeth are single-pointed.
Seven genera are counted to the subfamily Spiraxinae Baker 1939:
- Mayaxis Thompson, 1995
- Micromena HB Baker, 1939 - this was the type genus of the subfamily Micromeninae
- Miraradula Baker, 1939
- Pseudosubulina Strebel & Pfeffer, 1882
- Rectaxis Baker, 1926
- Spiraxis CB Adams, 1850
- Volutaxis Strebel & Pfeffer, 1882
The subfamily Euglandininae Baker 1941 includes six genera:
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Euglandina Crosse & P. Fischer, 1870
- Rosy wolf snail ( Euglandina rosea (Férussac, 1821))
- Guillarmodia HB Baker, 1941
- Pittieria by Martens, 1901
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Poiretia Fischer, 1883
- Poiretia algira (Bruguière, 1792)
- Dalmatian predatory snail ( Poiretia cornea (Brumati, 1838))
- Poiretia compressa (Mousson 1859)
- Poiretia delesserti (Bourguignat 1852)
- Poiretia dilatata (Philippi 1836)
- Varicoglandina Pilsbry, 1908
- Varicoturris Pilsbry, 1907
Five genera are counted to the subfamily Streptostylinae Baker 1941:
- Myxastyla Thompson, 1995
- Oryzosoma Pilsbry, 1891
- Salasiella Strebel, 1877
- Strebelia Crosse & Fischer, 1868
- Streptostyla Shuttleworth, 1852
literature
- HB Baker (1939): A revision of Spiraxis CB Adams . The Nautilus 53, 8-16.
- HB Baker (1941): Some Haplotrematidae . The Nautilus 54, 130-136.
- Fred G. Thompson (2010): Four species of land snails from Costa Rica and Panama (Pulmonata: Spiraxidae) . Revista de Biología Tropical (International Journal of Tropical Biology and Conservation) 58 (1), pp. 195-202.
- Philippe Bouchet & Jean-Pierre Rocroi: Part 2. Working classification of the Gastropoda . Malacologia, 47: 239-283, Ann Arbor 2005, ISSN 0076-2997 .
