Habitat and distribution

Concholepas concholepas is a benthic predator that lives on rocks in temperate waters from sea level to depths of 40 m.^[4] Its diet consists of mytilids (such as Semimytilus algosus and Perumytilus purpuratus) and barnacles (such as Chthamalus scabrosus).^[5]

Its geographic distribution ranges from Lobos de Afuera in Peru, to Cape Horn in Chile, including the Juan Fernández Islands.^[6]

Lifecycle

Concholepas concholepas is dioecious, which means the populations are divided between male and females, though with no external evidence of sexual dimorphism. The fertilisation in this species occurs internally.^[7] In central Chile, females lay egg capsules on low intertidal and shallow subtidal rocky surfaces during southern autumn months. After around one month of development inside the capsules, small planktotrophic veliger larvae (260 µm) are released. The larvae spend the following three months in the water column and once they become competent, they dwell at the sea surface until they settle on rocky intertidal and shallow subtidal habitats down to 30 m.^[4] The normal size at which the snail reaches sexual maturity is between 5.4 and 6.7 cm; it takes about four years to reach this size.^[8]

Commercial fishery

On the Chilean coast, C. concholepas is one of the most important edible mollusc species and is a major product of the aquacultural industry.^[10] In 1975, about 5,000 tons were extracted annually. In 1980, the extraction peaked, with a catch of 25,000 tons.^[11] Since 1989, extraction is illegal in Chile, but from 1992 onwards, some exceptions have been made for accredited commercial divers. The minimum size allowed for extraction is 10 cm. Currently, the only legal way for artisan fishermen or other people to catch locos is to have a Marine Area of Benthonic Resources Extraction permit. Even in these areas, though, extraction is prohibited from December to July from Valparaíso Region northward and from January or February to July south of it. Populations have shrunk and a recent study shows extraction is making an artificial selection to eliminate faster-growing individuals.^[6][12] The same study also showed the populations in Chile are relatively homogeneous with low genetic variability. Due to overextraction, scientists have studied the possibility of commercial cultivation since 1986.

Cuisine

In Chilean cuisine, the meat of the foot of these snails is cooked and eaten with mayonnaise or as a chupe de locos soup in an earthenware bowl. The chupe de locos typically contains about six snails' feet, 100 grams of a fatty cheese, such as Chanco cheese, two eggs, four spoons of grated bread, salt, and paprika.^[13]

Possible medical use

The hemocyanin found in the blood of C. concholepas has immunotherapeutic effects against bladder and prostate cancer. In 2006 research, mice were primed with C. concholepas before implantation of bladder tumor (MBT-2) cells. Mice treated with C. concholepas showed a significant antitumor effect. The effects included prolonged survival, decreased tumor growth and incidence and lack of toxic effects.^[14]

Other possible scientific uses

Concholepas concholepas shells are a potential proxy-bearer for climate change studies. There are many fossil shell accumulations in Pleistocene coastal terraces. Climate indicators are, by far, less abundant for ancient cold seas; therefore, investigating the ability of C. concholepas will provide valuable signals for long-term evolution of the sea surface temperatures in cold seas, and might be important in reconstructing the El Niño Southern Oscillation (ENSO) history.^[10]