Pike of Trasimeno
RISK OF EROSION: high
The Italian pike populations are largely at risk of erosion. On the basis of genetic studies carried out by the University of Perugia, it is possible to state that the Italian Pike population of Lake Trasimeno is one of the few, if not the only one, for which there is supportive morphological and molecular data, equipped with a homeostasis. long-term and low impairment by allochthonous Eastern European genotypes. This condition of reference population at national level is based on an evident precarious balance, which for Lake Trasimeno is due to the absence of inputs of fish material, to the activity of the Fish Center with capture-reproduction-re-introduction programs on site and to the prudent and respectful exploitation of the rules by professional fishermen.
Pike is one of the most characteristic and important species of Lake Trasimeno, from both an economic and ecological point of view. Pike is subject to sport and professional fishing and, being at the top of the food chain and being one of the most voracious predators, it has the fundamental role of regulating and controlling other fish species.
The presence of Pike in Italy, at least up to part of Lazio, is considered endemic. If you consult writings dating back more than ten years ago you can find the Pike indicated as allochthonous, but this evaluation has been revised and is now considered incorrect. To understand the distribution it is necessary to mediate the information currently available on the Italic species with that described in the past for Pike in general. In fact, in writings prior to 2011 it is mentioned only with the scientific name of E. lucius, this is because the Italic Pike had not yet been described as a “good species” (https://www.minambiente.it/sites/default/files/archivio/biblioteca/qcn_20.pdf). In particular, in Lake Trasimeno, the Pike is considered indigenous. There are no historical sources to support what is believed to be little more than a popular legend; it is said that the entry into the lake can be traced back to 1358 by the Sienese who wanted to damage the Perugini, destroying, with the voracity of the Pike, all the fauna present in the lake (Pizzul, 2017 http: // www. entetutelapesca.it/export/sites/default/it/istituzionale/documentazione/Pubblicazioni/ monographs / annexes / luccio.pdf). Moreover, the presence of Pike in Lake Trasimeno has been documented for several centuries, already before 1358, and is associated with both the beauty of the species and the importance it has always had for lake fishing. Historical documents are known that attest that its presence in the lake increased after 1266, the year in which the Perugian government approved the release of 10 some of pike (10 quintals). About ten years later in 1275 and then in the statute of the City of Perugia of 1279 the withdrawal from the Chiana river of at least 2,000 live pike was established to be introduced into Lake Trasimeno from February to March and from September to October. (Biganti, 1995 https://issuu.com/rivista.militare1/docs/34b._gli_archivi_per_la_storia_dell_alimentazione). Evidently in those decades this species was assuming particular importance, in fact, observing the north wall of the Upper Basilica of St. Francis of Assisi, almost above the altar, it is possible to admire a fresco by the Roman painter Jacopo Torriti, who between 1290 and 1295 he painted “The Creation of the World”. In this fresco a lake environment is represented, and given the proximity to Assisi it is assumed that it is Lake Trasimeno, in which the fish species present at the time are present in a clearly recognizable way, among which stands out, unequivocally, at the center of the scene, a Pike (Lucentini et al., 2010c). Among the historical sources that address the importance of pike for fishing, we can remember the works of the geographer abbot Bartolomeo Borghi of Monte del Lago. He published numerous works, including a manuscript of 1777, entitled News belonging to the Natural History of the Lake. Trasimeno today known as Perugia. Preserved in the municipal library of Magione, it is the first study that analyzes the geographic, physical and naturalistic aspects of Lake Trasimeno with scientific rigor, then taken up again in the work Geographic, physical and natural description of Lake Trasimeno, commonly known as the Lake of Perugia where it emerges the importance of pike fishing at the end of the 1700s (https://associazionearbit.it/descrizione-geografica-fisica-e-naturale-del-lago-trasimeno).
TYPICAL FARMING AREA
To date, it is particularly difficult to define the exact distribution range of pike species, especially due to the recent description of new species belonging to the genus Esox (Esox flaviae, Esox cisalpinus, Esox aquitanicus) (Lucentini et al., 2011; Bianco and Del maestro, 2011; Denys, Dettai, Persat, Hautecoeur & Keith, 2014) and the availability of molecular data only for two of them, as well as for E. lucius, attributable with certainty to representative specimens of the species. This aspect, in addition to a lack of correspondence between what is attributed as Italian pike without the aid of molecular data, is making the current taxonomy of the genus very confusing. The only certainty is the presence, within the Trasimeno lake, of specimens of Pike morphologically and genetically clearly distinguishable from those of Eastern Europe and most of northern Italy. The peculiarity of this population, whose genotypic traits have also been found in other Italian basins, does not lie in being an endemism, but in being, within the entire distribution range, the only genetically referable population, in toto, to the genotypes of Italian pike described in 2011 as E. flaviae.
TRADITIONAL BREEDING TECHNIQUES
The ecological, morphological and genetic characteristics of the Pike population (Esox flaviae) reflect the adaptation to the environment in which they live and in which they have evolved over thousands of years. It has a sensitivity to some environmental parameters, in particular the water temperature, the pH and trace of ammonia (Lucentini et al., 2010a). In particular, as regards the temperature, the aforementioned study demonstrates that the water temperature represents a source of variability that has evident monitorable effects on the ontogenesis of Pike. The data reported suggest that optimal temperatures in the development period should be between 5 and 10 ° C. The embryonic stages are delicate and environmentally sensitive stages, characterized by the highest intraspecific mortality rate. The knowledge of the developmental biology of Pike is therefore of considerable importance for the survival and conservation of the species. Furthermore, a probable determining factor for its proliferation was its reproductive period, slightly prior to that of the other species. Pike reproduces in Lake Trasimeno during the month of February and can prey on the juvenile stages of other fish species that generally reproduce in the following months, starting from March-April, such as the Perch or, in late spring, as most cyprinids.
Texts taken from “Regional register of autochthonous genetic resources of the Umbria Region”