. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. direct short medium long Mode of Larval Dispersal unknown. direct short medium long Mode of Larval Dispersal Figure 2. (a) Distribution of larval development modes lor the in- vertebrate species of Cobb Seamount. This presentation represents 95 invertebrate species. Details are given in Table I. Direct = species that have no pelagic stage; short = species with larvae pelagic for 2 weeks or less; medium = species with larvae that spend 2 to 8 weeks in the plank- ton; long = species with larvae that are pelagic for longer than
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. direct short medium long Mode of Larval Dispersal unknown. direct short medium long Mode of Larval Dispersal Figure 2. (a) Distribution of larval development modes lor the in- vertebrate species of Cobb Seamount. This presentation represents 95 invertebrate species. Details are given in Table I. Direct = species that have no pelagic stage; short = species with larvae pelagic for 2 weeks or less; medium = species with larvae that spend 2 to 8 weeks in the plank- ton; long = species with larvae that are pelagic for longer than 8 weeks. Above the columns are the numbers of invertebrates included, (b) Ex- pected distributions of larval development modes for benthic invertebrates around the latitude of Cobb Seamount; values generated from Thorson (1950, 1961) and Mileikovsky (1961) as explained in the text. Because these authors give different values for the proportion of species that are direct releasers, we present a distribution with a maximum value for direct release (black) and one using a minimum value (pattern). ways and individual adult migration. The nearest sea- mounts have summits below 500 m; only Union Sea- mount, 370 km north-north-west, is shallower. We believe present dispersal does play a major role. All but four undescribed amphipod species are found on the North American coast; several have wider distributions. The seamount sits at the divergence of an eastward flow field; flow further east splits into the Alaskan and Cali- fornia Currents. Two seasonal currents, shallow Davidson and deep California Undercurrent, flow poleward from California hugging the coast (Hickey, 1989). Stray jets may extend offshore occasionally, but even a 15 cm s~' current will take some 6 weeks to carry a larva from the coast. Medium- and short-duration larvae from sur- rounding continents are unlikely to survive the trip to Cobb. There are no other shallow seamounts nearby. The Alaskan gyre could bring lon
Size: 2035px × 1228px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
