This study in Lithuania showed that the abundance dynamics of the common dormouse (Muscardinus avellanarius) populations were comparatively “smooth”, without outbreaks and crashes. Decreases and increases of abundance continued for some years, and abundance differed no more than three-fold in two successive years. A close negative correlation was revealed between spring population density and percentage of juveniles in the autumnal population. The last parameter is a consequence of reproduction success, which determined the scale of population increase in autumn and was due to several factors. Among them, proportion of breeding adult females had the greatest significance and was inversely proportional to population density in spring. Some young-of-the-year females usually joined the breeding process, when population density was low. The proportion of late breeding cases, when juveniles were born in September, was also negatively correlated with spring population density. The number of litters produced by one female during the season, and the average litter size also influenced reproduction success. The negative correlation between population density and reproduction success shows the presence of a reproduction success based pattern of density dependent self-regulation in M. avellanarius in the populations investigated.
Five species of acanthocephalans of the family Centrorhynchidae are recorded from birds in Bulgaria: Centrorhynchus amphihius Das, 1950 from Buteo buteo (L.) (new host record), C. glohocaudatus (Zeder. 1800) Luhe, 1911 from Falco tin-nunculus L. and F. vespertinus L, (new host record), Sphaerimstris picae (Rudolphi, 1819) Golvan, 1960 from Pica pica (L.) and Lanius excuhitor L. (new host record), S. lancea (Westrumb, 1821) Golvan, 1960 from Vanellus vanellus (L.), and S. turili (Yamaguti, 1939) Golvan, 1960 from Turdus merula L„ Cinclus cinclus (L.) (new host record) and Stumus vulgaris L. (new host record). New geographical record for Europe is this of C. amphihius, and for Bulgaria - this of S. lurdi. The species are described and figured on the basis of Bulgarian specimens. Sphaerimstris picae is recognized as a valid species and S. teres is considered its synonym. A male of S. picae with a copulatory cap is reported.
A new species of Acanthochondria Oakley, 1927 (Copepoda, Poecilostomatoida, Chondracanthidae), parasitic on Serranus auriga (Cuvier) from the Argentinean coastal zone, is described and illustrated. The new species differs from its congeners by the relative length of the neck and the protopod of leg 2. This is the second record of this genus for the South-eastern Atlantic and the first one from a serranid host.
The following acanthocolpid species are reported from New Caledonia. Acaenodera nautili sp. n. from Conger cinereus Rüppel differs from other Acaenodera species in details of the body-spination, the sucker-ratio and the bipartite seminal vesicle; Stephanostomum murielae sp. n. from Carangoides hedlandensis (Whitley) differs from most species of Stephanostomum in the average of 36 circum-oral spines, the circum-oral spine rows with a ventral hiatus and the anterior extent of the vitellarium being >10% of the hindbody length from ventral sucker. The species is distinguished from the three other species with these characters in a detailed review. The other species reported are: Stephanostomum aaravi Bray et Cribb, 2003 from Lethrinus miniatus and L. rubrioperculatus; Stephanostomum ditrematis (Yamaguti, 1939) from Gnathanodon speciosus; Stephanostomum japonocasum Durio et Manter, 1969 from Cephalopholis urodeta, Epinephelus areolatus, E. chlorostigma, E. maculatus, E. retouti, Lethrinus miniatus and Variola louti; Stephanostomum uku Yamaguti, 1970 and Pleorchis uku Yamaguti, 1970 from Aprion virescens.