No abstract

A largely vacant niche in the upper mid-littoral zone of sheltered Hawaiian shores is now occupied by Chtharnalusproteus Dando & Southward, 1980 (Crustacea, Cirripedia), otherwise found in the Caribbean, the Gulf of Mexico and Brazil. The identity of the species was established by morphological details and confirmed by allozyrne electrophoresis. Previously, chthamaline barnacles have rarely been found fouling hulls of ships; this is the first recorded instance of regular occurrence on ships as well as of remote dispersal in the genus. While the introduction of C. proteus apparently has had little impact so far, there is a need to step up monitoring programs so as to prevent rather than simply detect future introductions.

No abstract

Since its first introduction in 1955, the snapper Lutjanus kasmira (taape) has developed large populations in shallow coastal waters of Hawaii. Visual abundance estimates and trap catches of taape were different between the main habitat types of the reef. Overall, taape was the second most abundant species by numbers and biomass over a hard substratum and was patchily distributed, even within habitat type. The largest individuals occurred singly or in small groups on shallow reef slopes; on the deep slopes and in spur-and-groove habitat, taape occurred in larger groups of smaller sized fish. Catches in fish traps showed a negative relationship with the complexity of the adjacent natural substratum, suggesting that traps are more productive where they offer additional cover in areas with less natural cover. In all areas in which traps were used, from fringing reef to open sand, the catch was dominated by taape. Tagging confirmed the theory that taape tend to maintain a limited range over long periods. Tagging results also indicated occasional long-range movements among major habitats and provided data confirming patterns of movement between reef habitat by day and sand habitat by night. Taape collected over open sand substratum by trap and by hook-and-line were smaller than those collected by the same means at the reef. Observations and collections suggested an ontogenetic trend in habitat use by taape from initial settlement in fringe areas toward ultimate residence on the main reef. Other common fish species in the reef assemblages were tested for statistical associations with taape. Although several positive species associations were found, multivariate analysis did not reveal patterns that indicated strong ecological relationships.