DEVELOPMENT, METAMORPHOSIS, AND SEASONAL ABUNDANCE OF EMBRYOS AND LARVAE OF THE ANTARCTIC SEA URCHIN STERECHINUS NEUMAYERI

Abstract

The development to metamorphosis of the shallow-water antarctic sea urchin, Sterechinus neumayeri, is described for the first time. Developmental stages are similar to those of closely related temperate species with feeding larvae, but the rate of development is extremely slow. Hatching of ciliated blastulae occurs approximately 140, 128, and 110 hours after fertilization at -1.8, -1.0, and -0.5°C, respectively, more than twice the time required for closely related temperate species near their normal ambient temperature. Larvae reared at -1.8 to -0.9°C are capable of feeding 20 days after fertilization and are competent to metamorphose after 115 days. Early cleavage embryos, blastulae, gastrulae, and prism larvae of this species were collected from the plankton adjacent to McMurdo Station, Antarctica, in early November and December, 1984 and 1985. Echinoplutei were not found during this study, but they have been collected from the plankton in other years; there is no evidence that the larvae are demersal. The timing of spawning ensures that feeding larvae are in the plankton during the abbreviated summer peak of phytoplankton abundance in McMurdo Sound. Recruitment of juveniles into the benthos most likely occurs in synchrony with the subsequent period of high levels of benthic chl a concentrations.

DNA photorepair in echinoid embryos: effects of temperature on repair rate in Antarctic and non-Antarctic species

“…Metabolic rates in Antarctic embryos are very low (Peck, 2002), with respiration orders of magnitude lower than in temperate counterparts (Hoegh-Guldberg et al, 1991). Growth rates and developmental times are similarly slower at lower temperatures (Clarke, 1992), with time to complete development ranging from 115·days in Sterechinus (Bosch et al, 1987), 30-60·days in Evechinus (Lamare and Barker, 1999) and 42·days in Diadema setosum (Onoda, 1936;Mortensen, 1937). Slow physiology as a general feature of Antarctic invertebrate embryos has been attributed to both low temperatures and nutrient constraints (low phytoplankton concentrations).…”

Brooding and Species Diversity in the Southern Ocean: Selection for Brooders or Speciation within Brooding Clades?

“…Two species, Sterechinus neumayeri and S. antarcticus, are abundant and widespread around the continental shelf (Brey and Gutt, 1991). The former is known to have typical echinoid planktotrophic development (Bosch et al, 1987). The other species are less well known and are taxonomically questionable but almost certainly also have pelagic development.…”

Growth and production of Sterechinus neumayeri (Echinoidea: Echinodermata) in McMurdo Sound, Antarctica

“…Spawning occurs in late austral spring to early summer (Pearse and Giese 1966;Yakovlev 1983), after an extended period of gametogenesis, with oogenesis requiring nearly 2 yr (Pearse and Bosch 1991). Development takes place in the water column and includes a typical pluteus larva; settlement and metamorphosis occur nearly 4 mo after fertilization (Bosch et al 1987).…”