Samples of anadromous Alosa alosa (Clupeidae) (n = 163) and Alosa fallax (Clupeidae) (n = 223), caught in Western Iberian Peninsula Rivers from 2008 to 2013, were examined for buccal, branchial and internal macroparasites, which were identified using morphological and molecular methods. Alosa alosa were infected with Anisakis simplex s.s., Anisakis pegreffii, Hysterothylacium aduncum, Rhadinorhynchus pristis, Mazocraes alosae, Hemiurus appendiculatus, Ceratothoa italica and an unidentified ergasilid copepod. Ceratothoa italica represents a new host record for A. alosa. Alosa fallax were infected with A. simplex s.s., A. pegreffii, H. aduncum, H. appendiculatus, Clavellisa emarginata and an unidentified cymothoid isopod. This is the first report of C. italica, C. emarginata and M. alosae in the Iberian Peninsula. The phylogenetic positions of M. alosae, H. appendiculatus and C. emarginata were assessed using 18S and 28S ribosomal RNA (rRNA); our contributions provide a better understanding of the phylogenetic relationships within their groups. Qualitative and quantitative differences in the parasite faunas of these two shad species are consistent with different feeding strategies. The results provide information about host migration behaviour and transmission pathways through diet during the marine trophic phase of the shad's life cycle and their roles as paratenic or final hosts and transporters of parasites between seawater and freshwater environments. The zoonotic parasites A. simplex s.s. and A. pegreffii pose a risk for consumers or riverine mammals (e.g. European otter). The use of parasites as biological tags for shad stocks in Western Iberian Rivers could be a useful approach in multidisciplinary studies concerning fish stock delimitation and characterization.

Three new species of myxosporeans are described from the gall bladders of Lophius piscatorius L. and L. budegassa Spinola. Ceratomyxa lophii n. sp. was found in 14 of 42 L. piscatorius from two locations to the northwest of Scotland in March 2000. Alataspora budegassai n. sp. was found in all eight specimens of L. budegassa caught off Algarve in the south of Portugal in June and August 2000. Pseudalataspora lophii n. sp. was found in 21 of 48 L. piscatorius from six locations to the west and northwest of Scotland in March 2000, March 2004 and October 2004. Ceratomyxa lophii n. sp. is one of only a few species of the genus having unequal spore valves, but differs from all the other species in spore dimensions and in the form of the plasmodium. The dimensions of the spore of Alataspora budegassai n. sp. are very similar to those of A. africana Shulman, Kovaleva & Dubina, 1979, described from a species of perciform fish caught off West Africa, but are markedly different from those of any of the other 15 described species of Alataspora. Pseudalataspora lophii n. sp. differs from the other 11 species of Pseudalataspora described to date in the dimensions of the spore and other features.