Friday 14 March 2014

Burtoa nilotica (Pfeiffer, 1861)

The word Molluscophobe is a curious one, I think. The discovery that the word exists - in that someone else mentioned they were one - makes me wonder whether there is some grainy Japanese horror film with a badly animated giant snail in the background eating Tokyo, broadcast only on late night TV when everything else on has someone translating the text into sign language in the corner of the screen.

I'm not sure it could be particularly effective, but then they've tried it with pigeons, so who knows?


Anyway, today's guest, in case you hadn't guessed, is a snail:
Photographed in Chongwe, Lusaka, Zambia, in December 2013, using an Olympus E-420 with Zuiko 40-150mm lens and 2 KOOD magnifiers. Possibly 1 KOOD magnifier, actually.
This lovely (to my eyes, at least) snail is difficult to identify when young, as its earthy-brown shell is the same colour as the closely related Giant African Landsnails of Achatina and Archachatina,and it's best identified by comparison by the much more common species, next to which they appear much blunter, with a wider foot that are very often folded as opposed to actually pulled into the shell.

The mature adults are much easier - they are a massive white snail. They are told apart by other massive white snails in the wider region (although there are none that I'm aware of in Lusaka) by a pinkish tinge around the lip of the shell and particularly, if you flip it over, the umbilicus (the gap in the middle, between the coils).

If you see this on a large (diameter of a tennis ball) white snail in south-central africa, you can be reasonably certain that you're looking at

Burtoa nilotica
(Pfeiffer, 1861)

As you might guess from its pale complexion, this snail is rarely seen in sunlight - I've mostly encountered them after heavy rain, usually at night although sometimes just in good shade. Although I've found a few around the sites of old fires, their most common appearances are around rotting fruit. They're also occasionally seen feeding on rotting animal matter, most notably dead Chongololos. 

Anyway, I think I've probably talked more than enough for one day, so on with the taxonomy: 

- Achatininae
- Achatinidae  
- Achatinoidea  
- Sigmurethra     
- Orthurethra       
- Elasmognatha     
- Stylommatophora 
- Eupulmonata         
- Pulmonata              
- Euthyneura              
- Heterobranchia          
- Gastropoda                  
- Conchifera                    
- Mollusca                         
- Lophotrochozoa                
- Protostomia                        
See also Ligia oceanica, Dicranopalpus ramosus, Hyllus argyrotoxus, Alopecosa barbipes, Enoplognatha ovataArgiope bruennichi, Pardosa amentata, Enallagma cyathigerum, Pseudagrion hageni, Lestinogomphus angustus, Rhyothemis semihyalina, Humbe tenuicornis, Lobosceliana loboscelis, Cyathosternum prehensile, Heteropternis thoracica, Stictogryllacris punctata, Tettigonia viridissima, Sibylla, Pephricus, Grypocoris stysiRanatra, Anoplocnemis curvipes, Synagris proserpina, Vespula germanica, Astata tropicalis, Anthophora furcata, Andrena nigroaenea, Zebronia phenice, Crambus pascuella, Nemophora degeerella, Sphinx ligustri, Laelia robusta, Acada biseriata, Metisella willemi, Anthocharis cardamines, Papilio demodocus, Panorpa germanica, Chloromyia formosa, Senaspis haemorrhoa, Helophilus pendulus, Episyrphus balteatus, Metadon inermis, Diasemopsis meigeniiDolichotachina caudata, Megistocera filipes, Hagenomyia tristis, Phyllobius pomaceus, Otiorhynchus atroapterus, Malachius bipustulatus, Oedemera nobilis, Melolontha melolontha, Cheilomenes lunata, Neojulodis vittipennis, Demetrias atricapillusAnthia fornasiini and Lophyra cf. differens.
- Nephrozoa                           
- Bilateralia                              
- Eumetazoa                              
- Animalia                                   
- Eukaryota                                  


You may very well note that the 'See also' bits here aren't a great organisational system - that's just a tragic sign that I've overlooked the first major terrestrial animals (Snails, being pretty much equipped for life on land or under water from the word go, were very early in their exploration of that brave new world above the strand line). Once more molluscs are identified and put up, it should start to look a little less... biased.

A final note before I go, if you encounter a large white snail such as this in Southern Africa,
Don't Kill It! 
As much as their relatives can be reasonably important (albeit edible) pests of subsistence-level farms, these ones favour decay and are actually very useful in recycling nutrients from dead vegetation to the soil. Like earthworms, but bigger and not remotely worm-like.



P.S. - I realise I've been overusing bold for emphasis in this one, just trying to mix things up a little, not intending to give headaches! 
 

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