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Studies on some cues regulating metamorphosis of the larvae of Balanus amphitrite (Cirripedia: Thoracica)

IR@NIO: CSIR-National Institute Of Oceanography, Goa

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Field Value
 
Contributor Raghukumar, S.
 
Creator Khandeparker, L.
 
Date 2006-06-28T07:30:20Z
2006-06-28T07:30:20Z
2002
 
Identifier Ph.D. thesis, Goa University- National Institute of Oceanography, Goa, India; 150p.
http://drs.nio.org/drs/handle/2264/161
 
Description Recruitment of the larvae of fouling organisms and their metamorphosis is the most important step in the fouling process. Cypris larvae does a substratum search before undergoing metamorphosis. The third antennular segment of the larva with its attachment disc is the most obvious point of contact during its search. The exploratory behavior and subsequent metamorphosis response of cypris when subjected simultaneously to sugars and adult extract (AE) is reported through this study. The detection of AE even after blockage of polar groups of cypris temporary adhesive (CTA) on the third antennular segment suggests availability of alternate sites for pheromone reception.Gregarious settlement in barnacles has been related to the settlement inducing compounds from adult conspecifics, microbes and their interaction. Efforts have been made to elucidate these settlement cues from these sources. The results indicated that the response of the cyprids towards bacteria and their products is regulated by both contact chemoreception and/or olfaction, depending on the properties of the settlement inducing compounds. It appears that lectins can provide this organism with an ability in altering the signals or cues. Microscale patchiness of bacteria is evidenced in marine communities. In view of this, and the conflicting cues available at the surface of the barnacle it is possible that such patchiness help piloting the larvae to the destination by the basibionts. Understanding these controlling mechanisms and interfering with the pathways that are involved in lectin synthesis would be a step ahead in antifouling technology. Thraustochytrid protists that have been detected in microbial films recently facilitated metamorphosis of cyprids to an even greater extent than adult extract (AE). It is likely that in nature, thraustochytrids on marine surfaces play an important role in the settlement of larvae belonging to macrofouling invertebrates. The need to characterize and distinguish the receptors, which act via different signaling systems on a particular settlement cue, will advance our understanding of the complexities of invertebrate larval recruitment. The variations in the larval response to different cues and the influence of aging of cyprids on larval metamorphosis can thus be related to the energy reserves and / or nutritional stress experienced by the larvae which is governed by naupliar rearing conditions. This will be of critical importance to recruitment and early post-settlement mortality.
 
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Language en
 
Title Studies on some cues regulating metamorphosis of the larvae of Balanus amphitrite (Cirripedia: Thoracica)
 
Type Thesis