The species composition of reef‐fish assemblages from nine Brazilian major coastal sites and four oceanic islands are compared. Canonical correspondence analysis (CCA) was utilized to identify groups of sites based on similarity of composition, and to correlate environmental trends with such groups. Five distinct groups of sites were recognized: (1) the South and South‐eastern coastal reefs (from Guarapari Islands to Santa Catarina, the southernmost Brazilian reefs); (2) the North‐eastern coast (extending from the Manuel Luis Reefs to Abrolhos Archipelago); (3) Trindade Island; (4) Fernando de Noronha and Atol das Rocas; and (5) St Paul’s Rocks. Water temperature, coral richness, distance from mainland, primary production and shelf width strongly correlated with the diversity and composition of the reef sites.

The perinatal development of anterior commissure projections was studied in hamsters by use of carbocyanine crystals implanted either into the commissure or into the ventrolateral prosencephalon. The earliest fascicles of growing commissural fibers had reached the midline on day 14 of gestation (E14). On E15, these fibers had entered the opposite hemisphere and reached the borders of their target regions. No waiting period was observed, since on E16 axons were already collateralizing into most targets. On P1, labelled cells were seen in all regions projecting through the anterior commissure in adults, namely, the anterior olfactory nucleus, olfactory tubercle, piriform cortex, nucleus of the lateral olfactory tract, bed nucleus of the stria terminalis, insular, perirhinal, entorhinal, and temporal cortices, as well as the amygdaloid complex. No evidence of topographical exuberance was detected. Counts of labelled neurons showed that the number of commissural cells increased gradually after birth. It is concluded that the development of paleocortical connections through the anterior commissure employs progressive strategies, lacking the regressive phenomena that are characteristic of the neocortical projections through the corpus callosum.

Elacatinus pridisi n. sp., a cleaner goby from Trindade Island, off Brazil, differs from its congeners of the Horsti Complex that have a pale stripe extending from the eye to the caudal fin base by the following combination of characters: dark longitudinal stripe wide, reaching lower abdomen and base of anal fin (vs. never reaching lower abdomen or base of anal fin in all other species); pectoralfin rays typically 18 (vs. typically 17 in E. randalli (B hlke & Robins) and E. figaro Sazima et al. and typically 16 in E. atronasum (B hlke & Robins)); anal-fin rays typically 11 (vs. typically 10 in E. figaro); a pale oval spot present on snout (vs. no spot in E. atronasum and E. horsti (B hlke & Robins), a "V"-shaped spot in E. prochilos (B hlke & Robins), and a medial bar in E. xanthiprora (B hlke & Robins), E. louisae (B hlke & Robins) and E. lori Colin). The new species was recorded in depths ranging from 3 to 30 m, over rocky reefs and calcareous-algae banks around the island. It has been observed in cleaning activities during the day with clients varying from large-sized carnivores such as Carcharhinus perezi (Poey) to small-sized planktivores such as Chromis multilineata (Guichenot). The discovery of the new species reinforces recognition of the Trindade-Martin Vaz insular complex as an area of endemism in the Atlantic Ocean.

Malacoctenus brunoi n. sp., a scaled blenny endemic to Trindade Island, is distinguished from its southwest Atlantic congeners by the combination of a higher number of lateral-line scales (typically 62-66), a more elongated body (depth 19-22 % SL), and the presence of two longitudinal series of dark brown spots alongside the body.

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