Evidence for protracted and lecithotrophic larval development in the yeti crab Kiwa tyleri from hydrothermal vents of the East Scotia Ridge, Southern Ocean

The deep-sea squat lobster Kiwa tyleri (also known as yeti crab) is the dominant macroinvertebrate inhabiting hydrothermal vents on the northern and southern segments of the East Scotia Ridge in the Southern Ocean. Here, we describe the first zoeal stage of the species—which is morphologically advanced—and provide evidence for its lecithotrophy in development. This morphologically advanced stage at hatching suggests that dispersal potential during early ontogeny may be limited. Adults of K. tyleri typically inhabit a warm-eurythermal, and spatially defined, temperature envelope of vent chimneys. In contrast, ovigerous females with late embryos are found away from these temperatures, off the vent site. This implies that at least part of embryogenesis takes place away from the chemosynthetic environment. Larvae are released into the cold waters of the Southern Ocean that are known to pose physiological limits on the survival of reptant decapods. Larval lecithotrophy may aid long developmental periods under these conditions and facilitate development independent of pronounced seasonality in primary production. It remains uncertain, however, how population connectivity between distant vent sites may be achieved.