Evolutionary trends within the genus Archiloa (Platyhelminthes, Proseriata)
Martens, P.M.; Curini-Galletti, M.C. (1993). Evolutionary trends within the genus Archiloa (Platyhelminthes, Proseriata). Belg. J. Zool. 123(Suppl. 1): 50
In: Belgian Journal of Zoology. Koninklijke Belgische Vereniging voor Dierkunde = Société royale zoologique de Belgique: Gent. ISSN 0777-6276; e-ISSN 2295-0451, more
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| Keywords |
Biological phenomena > Evolution
Archiloa de Beauchamp, 1910 [WoRMS]; Platyhelminthes [WoRMS]; Proseriata [WoRMS]
Marine/Coastal |
| Authors | | Top |
- Martens, P.M.
- Curini-Galletti, M.C.
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| Abstract |
We recently revised the Archiloa genus complex and recognised seven different genera of which phylogenetic relationships were hypothesised. Six of them are monophyletic and occur in restricted biogeographical areas. The genus Archilina Ax 1959, however, has a cosmopolitan distribution and is not characterised by an apomorphy, indicating the paraphy1etic status of this genus (Martens and Currini-Galletti, in press). The genus now contains 15 species from which el even are new (7 from the Mediterranean, 2 from the Red Sea and 2 from Puerto Rico). At this moment it is not yet possible to draw the phylogenetic relationships among all these species but some evolutionary trends can be recognised. In the two Caribbean species the bursa lies next to or behind the copulatory organ and both species have a karyotype deviating from that in the other Archilina species. These species may represent a separate evolutionary line within the genus. In three species from central Mediterranean the number of cirrus spines is reduced, and these three species probably constitute a monophyletic taxon. Other species from different geographical areas show a tendency to have enlarged proximal cirrus spines which can form a stylet- like structure or a true stylet within the cirrus originating from the fusion of the large proximal spines. This tendency seems to be a parallelism that arrised in the different geographical areas. |
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