by Tomislav Karanovic & Giuseppe L. Pesce

According to Bodin (1977) the tetragonicipitid genus Phyllopodopsyllus T. Scott, 1906, with 65 valid species and subspecies, is one of the most speciose marine harpacticoid genera, together with Halectinosoma Lang, 1944 and Stenhelia Boeck, 1865, and a marine harpacticoid genus with the largest number of new described species in the last fifty years.

Lang (1944) divided the original genus Phyllopodopsyllus in two genera (Phyllopodopsyllus and Paraphyllopodopsyllus Lang, 1944) on the basis of the shape of the second segment of antennula and the setation of the second and third swimming legs in the females. Many authors followed this revision, and Vervoort (1964) provided a useful key to the species of the genus Phyllopodopsyllus, although not for Paraphyllopodopsyllus.

Lang (1965) reconsidered his previous vue and synonymized Paraphyllopodopsyllus with Phyllopodopsyllus after several new species were described possessing intermediate caharacteristics. He compiled an excellent key to 21 species recognized at that time, and subdivided the genus into three morphological groups on the basis of the morphology (i.e. presence or absence, and dimensions of an unguiform projection) of the second antennular segment.

Later on Coull (1973) presented a very detailed subjective survey of the genus Phyllopodopsyllus, and compiled a most instructive table listing the most salient morphological characteristics. His key, untill today the most recent one, comprised 33 species and subspecies.

The last critical review of the genus was provided by Kunz (1984), who pointed out relationships betwen the genera and species within the family Tetragonicipitidae, representing their phylogenetic affinities, as well as subdivided the genus Phyllopodopsyllus into nine different species-groups, viz. bradyi, furciger, borutzkyi, pauli, opistoceratus, aegypticus, mossmani, xenus and longipalpatus, according to the shape and oligomerization and setation of antenna, antennula and swimming legs 2 to 4.

More recently, Bodin (1988) and Mielke (1989) followed the above subdivision; Fiers (1995) criticized the naturalness of the above groups definitions, even if he suggested that the group definition of the genus could be a most practical identification tool.

From an ecological point of view, the genus Phyllopodopsyllus is widespread in marine coarse sand and shell gravel of the intertidal zone, with a single citation (Phyllopodopsyllus sp.) for strictly interstitial fresh waters of Italy (Cottarelli et al., 1996).