Description: Gastropod molluscs with a single shell which cling to rocks. The shell is light coloured, rugged and irregular. The foot is yellow or bright orange. Limpets have a very powerful muscled foot with which they move and cling to the rocks in the sub-tidal and inter-tidal areas.
Global Distribution:Patella aspera occurs in the Macaronesian archipelagos of Madeira, Azores and the Canary Islands. It has recently been genetically distinguished from the closely related Patella ulyssiponensis, which occurs further north, in continental European coasts.
BIOLOGICAL FEATURES
Size: Legal size 40 mm minimum length.
Age:
Weight length rel.:
Growth type:
von Bertallanfy growth parameters:
Reproduction: Reproduction is sexual. Spawning occurs in Autumn and Winter, with a peak in December. Both males and females release their gametes into the water during the reproductive season. The eggs develop into planktonic trocophore larvae, with are transported by currents and disperse into different areas.
Maturity:
Behavioural ecology:
Population structure & migrations:
ECOLOGICAL FEATURES
Depth range: 0-6 m depth; occasionally deeper.
Habitat: Rocky inter-tidal and sub-tidal areas.
Feeding habits: They are herbivorous, feeding on microalgae and bacteria which they scrape from the rocks using the radula, a hard structure with multiple teeth.
Trophic level:
FISHERIES
Commercial interest: Exploitation of limpets in Madeira is a tradicional activity, especially amongst coastal populations who collect these molluscs in rocky intertidal areas. Both amateur and professional collectors engage in this activity, which involves freediving and using a 'lapeira' (a sort of chisel to dislodge the limpets). This is the only legally permitted collection method, and it targets the sub-tidal limpet populations of Madeira and Porto Santo rocky shores. Collection of limpets for personal consumption does not require a licence and is limited to 3 kg/day/person. Commercial collection requires a licence and is limited to 200 kg/day/boat.
Collecting limpets is forbidden from December 1st to February 28th, a period which encompasses a significant part of the reproductive period of both commercial limpet species.
Conservation status: Not evaluated.
Nutritional information & food safety:
Proximate composition per 100 g (estimated from other limpet species):
energy value 79.7 kcal (4.0% DRV)
protein 9.2 - 13.5 g (18.4 - 27.0% DRV)
fat 1.2 - 2.4 g (1.7 - 3.4% DRV)
of which saturates 0.446 - 0.893 g (2.2 - 4.5 %DRV)
omega-3 (EPA+DHA): 0.217 g (recommended: 0.250 - 2.0 g daily)
REFERENCES
Direcção de Serviços de Investigação e Desenvolvimento das Pescas, Direcção Regional de Pescas, Madeira.
Direcção Regional de Pescas, Madeira.
IUCN (2014). The IUCN Red List of Threatened Species. Version 2014.1. www.iucnredlist.org
Taboada C., Millán R., Miguez I., Fernández-Pulpeiro E. (2008). Composición en macronutrientes, aminoácidos y minerales de algunos invertebrados marinos no utilizados habitualmente como alimento. Revista Real Academia Galega de Ciencias, 27: 95-106.
Vlieg, P., 1988. Proximate Composition of New Zealand Marine Finfish and Shellfish, Palmerston North: Biotechnology Division, Department of Scientific and Industrial Research. In Smith I. (2011). Meat Weight, Nutritional and Energy Yield Values for New Zealand Archaeofauna. Otago Archaeological Report No. 8, 25 pp.
Weber L.I., Hawkins S.J. (2005). Patella aspera and P. ulyssiponensis: genetic evidence of speciation in the North-east Atlantic. Marine Biology, 147(1): 153-162.
Zlatanos S., Laskaridis K., Sagredos A. (2009). Determination of proximate composition, fatty acid content and amino acid profile of five lesser-common sea organisms from Mediterranean Sea. International Journal of Food Science and Technology, 44: 1590-1594.
