Lissachatina - Achatina Unterschied

Besonderheiten der unterschiedlichen Arten und Achatschnecken-Bestimmungsecke.

Lissachatina - Achatina Unterschied

Beitragvon Gabi am 10.03.2006 am 11:04

Im Angebote/Gesuche Bereich kam diese Frage auf und ich denke, hier passt sie besser rein.

Ich hab Paul gefragt und er hat das als Antwort geschrieben (übersetzen möge es sich jeder selber oder es findet sich jemand, der es tut):

PAUL ORIGINALKOPIE:

Lissachatina have smooth nepionic whorls (whorls formed in the egg).

Achatina have granulated nepionic whorls (like granules of rice).

You'll need a good magnifying glass to be sure, 10x or better and obviously in old shells the granules can be worn off.

When "Studies in the Achatininae, a group of African land snails - Joseph C. Bequaert" was published in 1950, these distinctions were subgenera so you would have:

Achatina (Achatina) achatina
Achatina (Lissachatina) fulica

According to the British Natural History Museum, Prof. Albert Mead has since advised that they'd have to be raised to genus level giving Lissachatina fulica etc...

But... he has yet to say which snails are still in which categories after study of the sex organs. So for now they stay at subgenus level. My site still lists fulica as Lissachatina fulica but I intend to change this back to Achatina (Lissachatina) fulica until we know more.

Also, the last categorisation was done by Bequaert in 1950 and he states what they are, as I explained above. So if Albert Mead decided to reclass all the snails, he'd probably have to make up new subgenera or redefine the existing ones based on completely different critera.

Hope this is explained clearly enough

PAUL ORIGINALTEXT die 2.:

Here is the exact text for both, it's hard to understand in english, not sure how easy it will be after translation, but my summary is good enough to prove them as sub-genus Achatina or Lissachatina:

Subgenus Achatina

..comprises large to medium-sized species, with a broadly ovate, elongate ovate or subglobular shell, and a regular conical spire, the summit a bluntly angular cone, not narrowly drawn out at the tip. The nepionic whorls, when in tact, as in newly hatched shells, are almost entirely covered with granulations in closely set, regular, spiral and vertical rows. Later whorls have either granulose, decussate, wavy or striate sculpture, or are almost smooth.

Subgenus Lissachatina

Nepionic whorls of newly hatched snails without granulation or decussated sculpture, either completely smooth or with faint vertical wrinkles; in older shells these early whorls are sometimes corroded and irregularly pitted or rugose. Post-nepionic whorls granulose or decussate; the sculpture sometimes very weak or evanescent on the body-whorl of adult shells. Apex of full-grown shell either of the usual conical shape or more or less drawn out into a narrow nipple, in which case the nepionic whorls may eventually break off. Most species are large or medium-sized, broadly ovate, elongate or spindle-shaped; a few are slender and shaped like Pintoa or Limicolaria, differing from the former in the smooth nepionic whorls and from the latter in the truncate columella.
LG, Gabi
Gabi
 
Beiträge: 247
Registriert: 06.11.2005 am 11:27

Zurück zu Achatschnecken - Artenspezifisches

Wer ist online?

Mitglieder: shakysan