Document Type

Article

Department/Program

Virginia Institute of Marine Science

Publication Date

1990

Journal

Bulletin of Marine Science

Volume

46

Issue

11

First Page

214

Last Page

229

Abstract

Daily, monthly and annual settlement of dominant brachyuran megalopae on six replicate artificial settlement substrates (collectors) was examined at one site in the York River, Virginia, from mid-July or early August to early December during 1985-1988. Callinectes sapidus Rathbun, an exported estuarine species, and Neopanope sayi (Smith), a retained estuarine species, were the numerically dominant colonizers of collectors. C. sapidus settlement was highly episodic (l-3-day duration) and significantly associated with the full moon period (lunar day 15-22). The temporal mean of settlement for C. sapidus each year fell within a 12-day period (24 September-6 October) over the 4 years. C. sapidus megalopae settled over a broad range of temperatures (7-3 1°C)extending into the fall months when resident predators become inactive or migrate to deeper water. In contrast, N. sayi settled throughout the lunar month with no significant lunar or tidal periodicity. Settlement by N. sayi occurred over a narrower temperature range (12-31°q than that for C. sapidus, and mean annual settlement for N. sayi occurred earlier within a 12-day period from 9-21 September. A behavioral and physiological mechanism is invoked to explain the observed pattern of C. sapidus settlement. We postulate that synchrony in settlement over a broad temperature range may reduce predation in C. sapidus.

Download

Share Feedback

Share

COinS