How and why diverse sexual systems evolve are fascinating evolutionary questions, but few empirical studies have dealt with these questions in animals. Pedunculate (gooseneck) barnacles show such diversity, including simultaneous hermaphroditism, coexistence of dwarf males and hermaphrodites (androdioecy), and coexistence of dwarf males and females (dioecy). Here, we report the first phylogenet...

The difficulty of obtaining in the laboratory massive liberation of barnacle nauplii com­ parable with that which occurs in nature led to an investigation of the effect of various factors on the hatching process. The hatching of egg masses in vitro is inhibited only at such low oxygen concentrations as to make the control of hatching by oxygen tension unlikely. Variations in salinity are simila...

Abstract Breakdown of skeletal and lithic hard substrates by organisms, a process referred to as bioerosion, is part the global carbon cycle receives increased attention, but little known about bioerosion in polar environments. Here, we study traces (addressed their respective ichnotaxa) recorded barnacle Bathylasma corolliforme from Ross Sea, Antarctica. Traces were visualized via scanning ele...