Threatened fishes of the world: Ladigesocypris ghigii (Gianferrari, 1927) (Cyprinidae)
Maria Th. Stoumboudi (a), Roberta Barbieri (a), Zissis Mamuris (b), Maria J. Corsini-Foka (c) & Alcibiades N. Economou (a)
(a) National Centre for Marine Research, Institute of Inland Waters,
Agios. Kosmas, 16604 Athens, Greece
Conservation status: Endangered, Greek red book, IUCN International
Red List, protected by Presidential Decree No. 67/1981 of the Greek State.
Identification: Small-bodied freshwater cyprinid (max SL: female=9.0 cm; male=6.5 cm) (Stoumboudi et al. in press). Dorsal silver-dark and ventral silver-bright coloration. D III/7-9, A III/(7)8-9, Sq.Lat. 27-32, incomplete lateral line (4-27), mouth terminal (Karaman 1972).
Drawing by Roberta Barbieri.
Distribution: Ghizani is endemic to Rhodes island (Greece). Inhabits most of the island's freshwater systems (streams, springs, weirs and pools). Previous surveys refer the presence of the species in the streams of Loutanis, Gadouras and Argiros, in Psinthos area (Pelemonis stream system), Agia Eleoussa, in Asklipion area (Kontaris stream), lake Nani, as well as in the artificial lake Apolakkia and its adjustent streams (Economidis 1988, Corsini 1994). During a recent survey, L. ghigii was additionally found in some new locations, namely the streams of Makaris, Chas, Kremastinos and Paradisiotis, while it was not found in lake Nani and the artificial lake Apolakkia (Stoumboudi et al. 2000, unpublished data).
Abundance: Varies considerably, according to the water quantities available.In recent years all populations exhibit tendencies of persisting decline, due to high mortalities occurring during the dry season. The populations of Gadouras Loutanis and Kontaris streams appear to be more abundant, compared to all the rest (unpublished data).
Habitat and ecology: Ghizani is a strongly opportunistic species. It prefers rather slow waters, staying close to the banks (favorite niches: roots of trees, bank cavities and, when present, among vegetation). In nature it lives up to three years and only in special conditions (e.g. captivity) its life span can be prolonged (Stoumboudi et al. 2000). Diet composition includes a wide range of small aquatic invertebrates and algae, with a prevalence of plant material during summer (unpublished data).
Reproduction: Ghizani is a fractional spawner reproducing mainly in late spring and early summer (Stoumboudi et al. in press). It matures at age 1 and deposits adhesive yellowish eggs (1.3 mm diameter) on aquatic filamentous algae. Artificial fertilization and rearing experiments, as well as egg and larva characteristics have been described (Barbieri et al. 2000, Stoumboudi et al. in press).
Threats: Summer drought and concomitant, unregulated water over-pumping cause continuous habitat degradation and/or loss, leading to massive fish deaths. Stream channelization and construction of dams lead to partial loss or fragmentation of populations. Introduction of alien species and of parasites that they host further weaken certain populations. In five ghizani populations examined so far, genetic intra-population variation was extremely low (unpublished data), thus increasing the risk of population collapse.
Conservation actions: A LIFE-Nature project is in progress (B4-3200/98/445), to implement management actions for ghizani conservation within the two NATURA 2000 sites of Rhodes (Stoumboudi 2000). These actions include the construction of a pilot fish refuge at Loutanis stream that aims to enhance summertime population survival.
Conservation recommendations: Regulated, sustainable management of the island's water resources is the key issue for the survival of all L. ghigii populations. Broadening of the NATURA 2000 sites to include more L. ghigii populations. Construction of more fish refuges.
Remarks: Genetic analyses also revealed high inter-population
genetic structuring (unpublished data). Consequently, populations should
be managed and conserved separately. Enhancement stockings, with translocations
of individuals from one site to another, are not recommended.