Chemical induction of larval settlement and metamorphosis in the reef-building tube worm Phragmatopoma californica (Sabellariidae: Polychaeta)

1986 ◽  
Vol 91 (1) ◽  
pp. 59-68 ◽  
Author(s):  
J. R. Pawlik
Keyword(s):  
Larval Settlement ◽  
Chemical Induction ◽  
Phragmatopoma Californica ◽  
Settlement And Metamorphosis

Larval settlement and metamorphosis of two gregarious sabellariid polychaetes:Sabellaria alveolatacompared withPhragmatopoma californica

1988 ◽  
Vol 68 (1) ◽  
pp. 101-124 ◽  
Author(s):  
Joseph R. Pawlik
Keyword(s):  
Larval Settlement ◽  
Larval Metamorphosis ◽  
Specific Mechanism ◽  
The West ◽  
Cemented Sand ◽  
Larval Behaviour ◽  
Naturally Occurring ◽  
Phragmatopoma Californica ◽  
Settlement And Metamorphosis ◽  
High Concentrations

Two sabellariid polychaetes,Sabellaria alveolatafrom European waters andPhragmatopoma californicafrom the west coast of North America, are known from previous work to have larvae that settle and metamorphose preferentially on the cemented sand tubes of conspecific adults. The naturally occurring inducers of larval metamorphosis were recently isolated and identified forP. californica.In the present study, larval behaviour ofS. alveolataandP. californicawas compared in reciprocal laboratory settlement assays. For both species, metamorphosis occurred to a greater extent on conspecific tube sand than on control sand or on heterospecific tube sand. Extraction of the tube sand ofS. alveolatawith organic solvents diminished its capacity to induce metamorphosis pi conspecific larvae, but this capacity was not transferred to the extracts, as was the case forP. californica. The substance responsible for the enhanced metamorphosis ofS. alveolataon conspecific tube sand remains unknown. The free fatty acid (FFA) inducers of larval metamorphosis ofP. californicaeither inhibited, or had no effect on, metamorphosis ofS. alveolata. Both species responded abnormally upon exposure to unnaturally high concentrations of certain (particularly polyenoic) FFAs. Abnormal larval responses ofS. alveolata, however, did not incorporate behavioural components of normal metamorphosis, as were observed forP. californica. FFAs were isolated from the natural tube sand ofS. alveolataat less than one-tenth the concentration found in the natural tube sand ofP. californica. The differences between the two species provide further evidence that a very specific mechanism is responsible for the perception of FFAs by the larvae ofP. californica.

Calcified macroalgae and their bacterial community in relation to larval settlement and metamorphosis of reef-building coral Pocillopora damicornis

2020 ◽  
Vol 97 (1) ◽  
Author(s):  
Fangfang Yang ◽  
Jiahao Mo ◽  
Zhangliang Wei ◽  
Lijuan Long
Keyword(s):  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Larval Settlement ◽  
Pocillopora Damicornis ◽  
Principal Coordinates Analysis ◽  
Principal Coordinates ◽  
Coral Reef Ecosystems ◽  
Settlement And Metamorphosis ◽  
Invertebrate Larvae

ABSTRACT Calcified macroalgae play an important role in the settlement and metamorphosis of invertebrate larvae in coral reef ecosystems. However, little is known about the algal-associated bacterial communities and their effects on larval settlement. In this study, the responses of larvae of the coral Pocillopora damicornis to calcified algae (Porolithon onkodes, Halimeda cylindracea, Halimeda opuntia and Amphiroa fragilissima) were evaluated. The results revealed that Por. onkodes and H. cylindracea significantly enhanced the rates of settlement and metamorphosis, whereas fewer larvae settled on Am. fragilissima and H. opuntia. Amplicon pyrosequencing of the V3–V4 region of 16S rDNA was applied to investigate the relationship between algal bacterial community and larval settlement. Principal coordinates analysis demonstrated that the bacterial community composition of H. opuntia was more similar to that of Am. fragilissima, but clearly distinct from those of H. cylindracea and Por. onkodes. Furthermore, the relative abundances of bacteria were highly diverse among different algae. H. opuntia had higher percentages of Thalassobius, Pelagibius and SM1A02, whereas the abundances of Mycoplasma and Suttonella were significantly higher in H. cylindracea than other algae. Our results showed that larval settlement/metamorphosis was strongly correlated with the bacterial community composition and with the relative abundance of a few operational taxonomic units.

scholarly journals Bacterial Nucleobases Synergistically Induce Larval Settlement and Metamorphosis in the Invasive MusselMytilopsis sallei

2019 ◽  
Vol 85 (16) ◽  
Author(s):  
Jian He ◽  
Qi Dai ◽  
Yuxuan Qi ◽  
Pei Su ◽  
Miaoqin Huang ◽  
...  
Keyword(s):  
Marine Invertebrates ◽  
Larval Settlement ◽  
Aquatic Systems ◽  
Substrate Selection ◽  
Content Type ◽  
Dreissenid Mussels ◽  
Settlement And Metamorphosis ◽  
Environmental Bacteria ◽  
Fouling Organisms ◽  
Chemical Mediators

ABSTRACTMarine bacterial biofilms have long been recognized as potential inducers of larval settlement and metamorphosis in marine invertebrates, but few chemical cues from bacteria have been identified. Here, we show that larval settlement and metamorphosis of an invasive fouling mussel,Mytilopsis sallei, could be induced by biofilms of bacteria isolated from its adult shells and other substrates from the natural environment. One of the strains isolated,Vibrio owensiiMS-9, showed strong inducing activity which was attributed to the release of a mixture of nucleobases including uracil, thymine, xanthine, hypoxanthine, and guanine into seawater. In particular, the synergistic effect of hypoxanthine and guanine was sufficient for the inducing activity ofV. owensiiMS-9. The presence of two or three other nucleobases could enhance, to some extent, the activity of the mixture of hypoxanthine and guanine. Furthermore, we determined that bacteria producing higher concentrations of nucleobases were more likely to induce larval settlement and metamorphosis ofM. salleithan were bacteria producing lower concentrations of nucleobases. The present study demonstrates that bacterial nucleobases play an important role in larval settlement and metamorphosis of marine invertebrates. This provides new insights into our understanding of the role of environmental bacteria in the colonization and aggregation of invasive fouling organisms and of the metabolites used as chemical mediators in cross-kingdom communication within aquatic systems.IMPORTANCEInvasive species are an increasingly serious problem globally. In aquatic ecosystems, invasive dreissenid mussels are well-known ecological and economic pests because they appear to effortlessly invade new environments and foul submerged structures with high-density aggregations. To efficiently control exotic mussel recruitment and colonization, the need to investigate the mechanisms of substrate selection for larval settlement and metamorphosis is apparent. Our work is one of very few to experimentally demonstrate that compounds produced by environmental bacteria play an important role in larval settlement and metamorphosis in marine invertebrates. Additionally, this study demonstrates that bacterial nucleobases can be used as chemical mediators in cross-kingdom communication within aquatic systems, which will enhance our understanding of how microbes induce larval settlement and metamorphosis of dreissenid mussels, and it furthermore may allow the development of new methods for application in antifouling.

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