Heterotrophic flagellates and centrohelid heliozoans from marine waters of Curacao, the Netherlands Antilles.

Recent progress in understanding the early evolution of eukaryotes was tied to morphological identification of flagellates and heliozoans from natural samples, isolation of their culture and genomic and ultrastructural investigations. These protists are the smallest and least studied microbial eukaryotes but play an important role in the functioning of microbial food webs. Using light and electron microscopy, we have studied the diversity of heterotrophic flagellates and centrohelid heliozoans from marine waters of Curacao (The Netherlands Antilles), and provide micrographs and morphological descriptions of observed species.

A new species of Cottus from the Onega River drainage, White Sea basin (Actinopterygii: Scorpaeniformes: Cottidae).

Cottus gratzianowi, a new cottid species, is described from material collected in the Ukhtomitsa River in the Onega River drainage, White Sea basin. It differs from its congeners in Europe east of the Meuse except C. koshewnikowi by having no transverse dark bands on the pelvic fin, a single chin canal pore, an incomplete lateral line not reaching behind the anal-fin insertion, and the position of the lateral line which is located considerably above the mid-line of the flank.

Under cover of darkness: nocturnal life of diurnal birds.

Songbirds are generally considered diurnal, although many species show periodic nocturnal activity during migration seasons. From a breeding-range perspective, such migratory species appear to be diurnal because they are observed to nest and feed their young during the day. But are they really exclusively diurnal? The authors tested how a passerine long-distance migrant, the Eurasian reed warbler, schedules movements during the breeding period by tracking birds in 2 experimental situations: 1) Birds experienced simulated nest loss and were monitored during their search for alternative locations, and 2) birds were translocated to reed beds at distances from 2 to 21 km and tracked during homing.