 |  |
|
Amphipods are peracarid crustaceans widespread on the Planet and very common in surface, marine, brackish and fresh waters, and in a wide range of groundwater environments. A few gammaridean amphipods are semiterrestrial, living in moist forest leaf litter or on sandy beaches. The order comprises about 6700 species, distributed among three (Gammaridea, Caprellidea, Hyperiidea) or four (Gammaridea, Caprellidea, Hyperiidea, Ingolfiellidea) suborders, according to Holsinger (1994) and Stock (1986) respectively. Approximately 35 families and 133 genera include subterranean, mostly stygobitic, amphipods, and this number rapidly increases following new discoveries in different groundwater habitats of the World. The suborder Gammaridea, and the families Niphargidae, Hadziidae s.l., Bogidiellidae and Gammaridae include the majority of stygobitic taxa, the remaining families contain fewer, in many cases one-two, genera.
Amphipods of the italian stygofauna include 12 genera, viz. Niphargus, embracing the greater part of the known species and subspecies of the italian amphipods, Pseudoniphargus, Salentinella, Ingolfiella, Metaingolfiella, Bogidiella, Aurobogidiella, Ilvanella, Rhipidogammarus, Tyrrhenogammarus, Hadzia and Carinurella, and 62 species and subspecies. Some species of the genera Sinurella and Neogammarus can be found in the ecotonic transition zone between surface and ground waters, but they do not show stygobitic adaptation features. A remarkable number of taxa are endemic to Italy, viz the family Metaingolfiellidae, with the monotypic genus Metaingolfiella, the genera Aurobogidiella, Ilvanella and Tyrrhenogammarus, and about 40 species and subspecies belonging to the genera Niphargus and Bogidiella. Stygobitic amphipods of Italy invaded subterranean waters from both freshwater and marine environments, involving active and passsive dispersal. Several genera (Bogidiella, Aurobogidiella, Salentinella, Hadzia, Pseudoniphargus, Rhipidogammarus, Tyrrhenogammarus and Ingolfiella) colonized the groundwater habitat directly from the sea; the genus Ilvanella probably reached the continental ground waters from epigean fresh water bodies; the species Niphargus elegans, which lives both in surface and ground waters, colonized the former habitat from underground waters; for the other genera, Niphargus and Carinurella, the origin and the subterranean waters colonization are uncertain; maybe they reached the continental groundwater systems directly from the sea (Tertiary, Parathetys) or, according to Ruffo (1982), from the tertiary Parathetys they colonized firstly the epigean and successively the continental ground waters of Italy. As regards the age of colonization, some species of the genera Bogidiella, Salentinella, Riphidogammarus and Pseudoniphargus, due to their high degree of salinity tolerance, are to be considered recent immigrants of continental subterranean waters; other ones, such as the species of the genera Hadzia, Ingolfiella,Tyrrhenogammarus and some Bogidiella colonized the italian ground waters in rather ancient age. The remarkable genus Metaingolfiella, which occupies an isolated systematic position among the amphipods, most probably is the most ancient amphipod taxon living in the italian ground waters. The genera Niphargus and Carinurella started their colonization from the tertiary Paratethys, during different ages. Finally, as regards the ecology, several italian amphipods can be related to the ground water quality: in fact, numerous species, for the most part belonging to the genus Niphargus, show a high sensitivity to the water pollution, as well as they rarefy or disappear when the ground waters are polluted.
Niphargus aberrans Sket 1972 (1) Genus Pseudoniphargus
Pseudoniphargus adriaticus S.Karaman 1955 (3,4,5) Genus Metacrangonyx Metacrangonyx ilvanus Stoch 1997 (Elba Island) *
Genus Bogidiella
Bogidiella (Bogidiella) albertimagni Hertzog 1933 (1) sub.gen. Medigidiella
Bogidiella (Medigidiella) chappuisi chappuisi Ruffo 1952 (2,3,4) Genus Aurobogidiella Aurobogidiella italica G.Karaman 1979 (3) * Genus Salentinella
Salentinella angelieri Delamare Deboutteville & Ruffo 1952 (1,2,3,4) Genus Hadzia
Hadzia adriatica Pesce 1979 (4) * Genus Ilvanella Ilvanella inexpectata Vigna Taglianti 1971 (2,3) * Genus Rhipidogammarus
Rhipidogammarus karamani Stock 1971 (3,4,5) Genus Tyrrhenogammarus
Tyrrhenogammarus catacumbae (G.Karaman & Ruffo 1977) (5) * Genus Carinurella Carinurella paradoxa (Sket 1964) (1)
Genus Ingolfiella
Ingolfiella (Tyrrhenidiella) cottarellii Ruffo & Vigna Taglianti 1989 (2) *
Genus Metaingolfiella
Metaingolfiella mirabilis Ruffo 1969 (4) *
Genus Longigammarus
Longigammarus planasiae Messana & Ruffo, 2001 (2) *
[Numbers between brackets according to the stygofaunal provinces of Italy]
A selected World bibliography on subterranean amphipods can be found in: Stock J. H. (1984). Amphipoda: Gammarid grouping (Gammaridae s.str. sensu Bousfield). Stygofauna Mundi: 497-503; Stock J. H. (1984). Amphipoda: Melitid grouping (Melitidae sensu Bousfield, 1973, emend.). Stygofauna Mundi: 504-513; Karaman G. S. & S. Ruffo. (1984). Amphipoda: Niphargus-group (Niphargidae sensu Bousfield, 1982). Stygofauna Mundi: 514-534; Holsinger J. R. (1984). Holarctic Crangonyctid amphipods. Stygofauna Mundi: 535-549; Ruffo S. (1984). Amphipoda: groupe Metacrangonyx. Stygofauna Mundi: 550-552; Williams W. D. (1984). Amphipoda on land-masses derived from Gondwana. Stygofauna Mundi: 553-559; Stock J. H. (1984). Amphipoda: Pleustidae. Stygofauna Mundi: 560-561; Stock J. H. (1984). Amphipoda: Phoxocephalidae. Stygofauna Mundi: 562; Stock J. H. (1984). Amphipoda: Liljeborgiidae. Stygofauna Mundi: 563; Ruffo S. (1984). Amphipoda: Salentinellidae. Stygofauna Mundi: 564-566; Stock J. H. (1984). Amphipoda:Pardaliscidae. Stygofauna Mundi: 567; Holsinger J. R. (1984). Amphipoda: Sebidae. Stygofauna Mundi: 568-569; Stock J. H. (1984). Amphipoda: Aoridae. Stygofauna Mundi: 570; Ruffo S. (1984). Amphipoda: Talitroidea. Stygofauna Mundi: 571-573; Coineau N. & J. H. Stock (1984). Amphipoda:Bogidiellidae. Stygofauna Mundi: 574-580; Stock J. H. (1984). Amphipoda: Ingolfiellidae. Stygofauna Mundi: 581-584; Holsinger J. R.(1994). Amphipoda. Encyclopaedia Biospeologica. Societè de Biospéologie, Moulis, Bucarest: 147-163.
A comprehensive, detailed list of italian freshwater amphipods, with emphasis to the groundwater taxa, can be found in:
|
Report comments and suggestions to