A new piece in the puzzle for the riverine slugs of the Acochlidiidae (Panpulmonata: Acochlidia)
WMC Azores, Portugal and 106th Annual Meeting of the German Zoological Society, Munich, Germany
|Type of Publication:||Congress Contributions and Posters|
Currently there are two known morphologically distinct taxa among acochlidiids: one lineage with the slender, uniformly reddish colored Strubellia (2 described species) which resembles the Pseudunelidae (the marine sister group of the Acochlidiidae), and a second lineage with seemingly more derived, flattened and pigmented, brown or greenish Acochlidium (3 sp.) and Palliohedyle (2 sp.).
A 2010 survey of freshwater gastropods on the Moluccan island of Amboina, Indonesia, discovered two specimens of a hitherto unknown acochlidiid that shows intermediate characters. Externally, it resembles a blue-green Strubellia, and 3-dimensional reconstruction based on semithin histological sections shows that digestive and excretory systems largely resemble that in Strubellia. Scanning electron microscopy and histology, however, shows that the species has evolved the complicated trap-like copulatory organ which resembles that of Acochlidium. A molecular phylogeny of acochlidiids using multilocus markers confirms that the species is indeed sister to a clade including Acochlidium and Palliohedyle. This suggests that a complex copulatory organ evolved earlier than the Acochlidium-like morphotype.
- 2013 A new piece in the puzzle (2 MByte)