Anadenidae
The Anadenidae are a family of nudibranchs from the suborder of terrestrial snails ( gastropod ). The few species are restricted to North India, Pakistan, Nepal, southern China and northern Vietnam.
Features
The representatives of the Anadenidae are all slugs with wurmförmigem body, it is medium to large slugs. The original housing is reduced to a flat, oval shell plate, which is completely enclosed by the sheath. This, in turn, occupies about half of the total length of the animal and substantially centrally or slightly behind the center of the shell is a blow hole ( Pneumostom ). The tail is without keels, the back of the foot is rounded and the foot itself undivided or only hinted divided into three parts ( lengthwise). The Anadenidae have a ribbed jaw, and with them the approach of the muscles of the Buccalapparates and the muscles of the tentacles are separated. Your genital apparatus has a long vas deferens ( vas deferens ), the distal part has been more or less clearly transformed into a epiphallus. The internal penis has an edge ( verge ); a stimulator or other solid elements ( spines, hooks or plates) may be present and even calcified. The spermatophore is slim, rolled up and ends in a thread-like end which is provided with a small hook.
Geographical distribution and behavior
The few species of the family are found in North India, Pakistan, Nepal, southern China and northern Vietnam. They live in evergreen forests up to higher elevations ( above 2000 m). The way of life is known only from a few species. Anadenus altivagus lives in evergreen oak forests in the Himalayan foothills of India in about 2000 m altitude. Although the animals are hermaphroditic, self-fertilization is not possible. From July to August therefore takes place the pairing and after only about 60-80 days, the eggs are laid (September / October). After oviposition the animals die. The eggs are about 6 mm in diameter is relatively large and the young hatch after 70 to 80 days after oviposition in December and January. The reasons for the hatching in winter are not known, however, remain the hatchlings in the ground and hold a winter rest. Only in the spring they leave the earth and be slow at first, later more rapidly gain weight. The following winter they turn hold a winter rest, to mate the following summer and lay eggs in the fall. The animals are also under laboratory conditions, not older than two years.
System
Schileyko (2007) provides only two genera, however, with several sub- genres in the Anadenidae family. In the original version, the family still contained the two North American genera Adenulus and Prophysaon. Later it turned out that these two genera can not be placed in the same family and the family was limited to the type genus and the closely related genus Anadenus Anadeninus Simroth. Overall, only slightly more than 20 species are known.
- Family Andenidae Pilsbry, 1948 Genus Anadenus Heyne Man, 1863 ( with the subgenera Anadenus ( Anadenus ) Heyne man, 1863 and AnadenusSagarmathia ) Kusminykh & Schileyko, 2006
- Genus Anadeninus Simroth, 1912 ( with the subgenera Anadeninus ( Anadeninus ) Simroth, 1912, Anadeninus ( Vietanadenus ) Kusminykh & Schileyko, 2006 Anadeninus ( Neoanadenus ) Wiktor, Chen & Wu, 2000)