46 DECEMBER 2012 • WORLD AQUACULTURE • WWW.WAS.ORG The carpione Salmo carpio is a strictly endemic salmonid of the largest lake in Italy, Lake Garda (volume = 49 km3, surface area = 368 km2, maximum depth = 350 m). Salmo carpio is a mediumsized trout, attaining a maximum total length of 35 to 40 cm and a maximum weight of approximately 500 g in the natural environment. Record trophy specimens might exceptionally reach 50 cm and one kilogram. The body shape of the carpione is characterized by a relatively small head. The background body color is silvery grey, with small blackish dots on the dorsal area. During spawning seasons, some sexual dimorphism can be observed, with males showing a dark bronze background and blackish fins (Fig. 1). Full sexual maturity of the carpione occurs at three years of age in males and at four years in most females, although some spawning may occur one year earlier (Melotto and Alessio 1990). The species is thought to be gregarious, particularly during seasonal migration between spawning and foraging areas. The diet of the carpione is mostly zooplankton (Alessio et al. 1990). Genetic diversity of the carpione was investigated by sequence analysis of the complete mitochondrial DNA control region (mtDNA D-loop) on a relatively high number of S. carpio and S. trutta samples from Lake Garda, prompting us to reconsider the proposed hypotheses on the origin and phylogeny of the taxon (Gandolfi et al. 2006). From a genetic viewpoint, extensive molecular screening, including sequencing of the complete mitochondrial DNA control region (mtDNA D-loop) and genotyping of highly-variable microsatellite loci, provide novel insights into phylogeny, population structure and conservation status of a taxon of interest (Gandolfi et al. 2006, Gratton and Gandolfi 2011). The carpione differs from other indigenous salmonids in Italy, such as the marble trout Salmo (trutta) marmoratus, on the basis of the temporal and spatial peculiarities of reproductive behavior. Eggs of the carpione are deposited during two spawning seasons, peaking in DecemberJanuary and July-August, in deep (50-200 m) lakebeds with abundant oxygen. Many authors suggest that each specimen reproduces either in winter or in summer, although the hypothesis of a unique, long spawning period has never been verified in the species’ natural environment. A Critically Endangered Species Carpione is considered critically endangered according to the Red List of Threatened Species (IUCN 2010), with most important threats being overfishing, habitat deterioration and introduction of exotic competitor species. In detail, the introduction of planktivorous whitefish Coregonus spp. in 1918 is generally thought to have promoted the demographic decline of the carpione. Historically carpione were caught intensively during spawning periods. The commercial catch was more than 20 t per year during the 1950s, but the population of S. carpio has been reduced drastically during the last decades (Fig. 2). Currently the only conservation actions concerning the carpione are the prohibition of fishing during spawning periods (15 November — 31 January and 20 June — 20 August), establishment of a minimum harvest size (30 cm), and the regulation of net size used by fishermen (Ciutti et al. 2010). Conservation also goes through ex situ multiplication. In Salmo carpio: an Endemic Salmonid of Lake Garda, Northern Italy Fernando Lunelli*1, Filippo Faccenda1, Ivano Confortini2, Cristina Cappelletti1 and Francesca Ciutti1 FIGURE 1. Figure 1. Male (a) and female (b) carpione during the spawning period. The body shape of the carpione is characterized by a relatively small head. The background body color is silvery grey, with small blackish dots on the dorsal area. The species is thought to be gregarious, particularly during seasonal migration between spawning and foraging areas. The diet of the carpione is mostly zooplankton. a. b.
RkJQdWJsaXNoZXIy MjExNDY=