Six Myxobolus species are described from Nile ®sh, ®ve of which are new and one is redescribed: M. naari Abdel Ghaar et al., 1998 was recovered from the gills of Labeo niloticus and the mouth of Barbus bynni; M. caudatus sp. n. was observed in the tail ®n of B. bynni; M. fahmii sp. n. occurred in the gills of B. bynni; M. imami sp. n. was found in the kidney of L. niloticus; M. intestinalis sp. n. was recorded from the intestine of B. bynni; and M. perforata sp. n. was found in the internal surface of the operculum of Hydrocynus forskalii. The histological eects of some of the Myxobolus infections present are described. ResultsAll the examined ®sh were found to harbor myxosporean infection except Tetradon fahaka and Mormyrus kannume. Myxobolus naari Abdel Ghaar et al., 1998 See Figs. 1a, 4a. Host B. bynni and L. niloticus. Site of infectionMouth of B. bynni and gills of L. niloticus.

No abstract

Marine reptile remains occur in the Upper Cretaceous (lower Campanian to lower Maastrichtian) Adaffa Formation of NW Saudi Arabia. This is the first detailed report of late Mesozoic marine reptiles from the Arabian Peninsula. The fossils include bothremydid (cf. Taphrosphyini) turtles, dyrosaurid crocodyliforms, elasmosaurid plesiosaurs, mosasaurs (Prognathodon, plioplatecarpines) and an indeterminate small varanoid. The assemblage is compositionally similar to contemporary faunas from elsewhere in the Middle East/North Africa, and comprises taxa that are typical of the southern margin of the Mediterranean Tethys.

Zschokkella helmii n. sp., a new parasite of Siganus rivulatus from the Red Sea, Egypt, was described using light and transmission electron microscopy. However, the infection was severe; single "histozoic" plasmodium was encountered in the gallbladder wall. Spores are ellipsoid with 9-11 valvar striations. Spore mean length is 10.8 microm (10.0-11.0), while the spore mean width is 7.5 microm (7.0-8.0). Polar capsules are nearly round with a diameter of 2.2 microm (2.0-3.0) and have five filaments. Ultrastructure of the plasmodial wall and sporogenesis of the present species followed the usual pattern valid for most studied myxosporean species.

Dinosaur remains from the Arabian subcontinent are exceedingly rare, and those that have been documented manifest indeterminate affinities. Consequently the discovery of a small, but diagnostic, accumulation of elements from Campanian-Maastrichtian (∼75 Ma) deposits in northwestern Saudi Arabia is significant because it constitutes the first taxonomically identifiable dinosaur material described from the Arabian Peninsula. The fossils include a series of possible lithostrotian titanosaur caudal vertebrae, and some isolated theropod marginal teeth that share unique character states and metric parameters (analyzed using multivariate statistical methods) with derived abelisaurids – this is the first justifiable example of a non-avian carnivorous dinosaur clade from Arabia. The recognition of titanosaurians and abelisaurids from Saudi Arabia extends the palaeogeographical range of these groups along the entire northern Gondwanan margin during the latest Cretaceous. Moreover, given the extreme paucity of coeval occurrences elsewhere, the Saudi Arabian fossils provide a tantalizing glimpse into dinosaurian assemblage diversity within the region.