Effect of age, injury, and predator odors or settlement and shelter selection by lobster Homarus amencanus postlarvae

Abstract

The effects of endogenous and exogenous factors on settlement and habitat selection behaviours of Homarus americanus postlarvae were studied under controlled conditions in the laboratory. Light level within shelters, a primary cue used in microhabitat selection by settling lobsters, was manipulated to create 4 microhabitats of different quality (= level of illumination). Preliminary experiments indicated that, when offered separately, low light intensity shelters induced more postlarvae to settle and seek a shelter than microhabitats presenting higher light levels. Choice experiments (all types of shelter offered simultaneously) were designed to test whether (1) delayed settlement, (2) injuries at metamorphosis (loss of one or both chelipeds), and (3) metabolites of the fish predator Tautogolabrus adspersus, Influenced settlement rate and selectivity of competent lobsters. Postlarvae settled more quickly and sheltered less selectively as they aged. Similarly, postlarvae released in seawater previously conditioned by T adspersus tended to exhibit a higher settlement rate and lower degree of selectivity than when tested In control (unconditioned) water. Lobsters which had lost both chelipeds at metamorphosis exhibited a reduced settlement rate compared to normal postlarvae or postlarvae with a single chela. Severely injured postlarvae also appeared less selective than normal or slightly injured postlarvae. Implications of these results for further habitat choice expenments are discussed.

Spatial variability in decapod community structure and recruitment in sub-tidal habitats

“…Many marine invertebrates release dispersive planktonic propagules as part of their reproductive life cycle. The postlarvae of many species have been shown to exhibit both positive and negative taxis towards various cues within the surrounding environment, including presence of algae and seagrass (Forward et al 1996, Morgan et al 1996, Welch et al 1998, habitat complexity (Moksnes et al 1998, Stevens & Kittaka 1998 and the presence or absence of conspecifics (Crisp & Meadows 1962, Jensen 1991 or predators (Boudreau et al 1993, Welch et al 1998, Diaz et al 1999. Late in the larval phase, at the time approaching metamorphosis when discriminatory ability increases (Welch et al 1998), the selection of a suitable habitat plays an important role in subsequent survival.…”

Lipid nutrition and settlement behaviour in American lobster Homarus americanus

“…Settlement is controlled by several biotic and abiotic factors (Butler et al 2006, Phillips et al 2006. For example, lobster postlarvae actively avoid predator odour plumes (Boudreau et al 1993a) and preferentially settle in lowlight shelters compared to microhabitats with higher light levels (Boudreau et al 1990(Boudreau et al , 1993b. Indeed, olfactory capacities and cryptic behaviour are likely to increase post-settlement survival in lobsters by improving predator avoidance.…”

Pueruli Settlement in the Caribbean Spiny Lobster, Panulirus Argus, at Bimini, Bahamas

“…Such a relationship applies particularly to NS, where prevailing winds are occasionally observed to offset tidal influences (Jacobsen, 1987). Moreover, pueruli settlement is known to be higher on structurally complex bottoms, especially if composed of seagrass and macroalgae, compared to soft, featureless substrata, and active seeking behaviour of pueruli for a particular settlement site has been described for several species of lobsters (e.g., Boudreau et al, 1993;Booth, 2002). Bathurst (1972) reported Bathophora sp.…”