The nuclear DNA content of Salmo fibreni, endemic to Lake Posta Fibreno, and of the sympatric Salmo trutta macrostigma, was evaluated using flow cytometric (FCM) analysis. The DNA content was 6·29 pg/nucleus for male and significantly greater at 6·41 pg/nucleus for female S. fibreni; and 6·37 pg/nucleus for male S. trutta macrostigma. 1996 The Fisheries Society of the British Isles

1. Riparian birds and macroinvertebrates were studied in five reaches of four tributaries of the Tiber river (Italy). The first aim was to check if stream quality, assessed by extended biotic index (EBI) values, could represent change in the riparian zone, assessed through the bird community. The second was to consider whether stream quality affects the presence of riverine bird species. 2. Stream quality and richness of the riparian bird community were related. In streams with more disturbed macroinvertebrate communities, but also in agricultural areas, the relative frequency of granivorous species increased in the riparian zone. 3. Dippers Cinclus cinclus occurred exclusively in reaches with the best stream quality, but the relationship between grey wagtails Motacilla cinerea and stream quality was less clear. 4. These results support the judicious use of riverine and riparian birds as biological indicators. Copyright © 1999 John Wiley & Sons, Ltd.

Highly developed adhesive structures are characteristic of the eggs of Odonthestes bonariensis. At spawning each egg is connected to the other ones by four to six filaments. These are extroverted only in mature eggs, about 4–5 mm long and 10μm thick, starting from coneshaped bases at the egg's surface. Histologically, no filaments are detectable during the primary growth phase of the oocytes. At the lipidic vesicle stage, rounded eosinophilic filaments appear at the cell's surface. During the following stages they increase in volume and length, running along the whole oocyte, and lose their eosinophily. The filaments are beneath the follicular cells; according to preliminary TEM observations, they derive from the zona radiata. When the oocyte is mature, the theca externa disintegrates, freeing the filaments. These rather conspicuous and complex structures are markedly different from the adhesive egg fibrils observed in other teleosts.

1. Riparian birds and macroinvertebrates were studied in five reaches of four tributaries of the Tiber river (Italy). The first aim was to check if stream quality, assessed by extended biotic index (EBI) values, could represent change in the riparian zone, assessed through the bird community. The second was to consider whether stream quality affects the presence of riverine bird species.2. Stream quality and richness of the riparian bird community were related. In streams with more disturbed macroinvertebrate communities, but also in agricultural areas, the relative frequency of granivorous species increased in the riparian zone.3. Dippers Cinclus cinclus occurred exclusively in reaches with the best stream quality, but the relationship between grey wagtails Motacilla cinerea and stream quality was less clear.4. These results support the judicious use of riverine and riparian birds as biological indicators.1. Farfa river (altitude 250 -300 m above sea level), characterized by modest human impact (Figure 2). Figure 1. Map of the study streams. The thick black lines are the regional limits, the thin lines are the rivers.