Limits...
Natural populations of shipworm larvae are attracted to wood by waterborne chemical cues.

Toth GB, Larsson AI, Jonsson PR, Appelqvist C - PLoS ONE (2015)

Bottom Line: Natural populations of teredinid larvae were significantly more abundant close to wooden structures enclosed in plankton net compared to empty control nets, clearly showing that shipworm larvae can sense and respond to chemical cues associated with suitable settling substrate in the field.However, the flume experiments, using ecologically relevant flow velocities, showed that the boundary layer around experimental wooden panels was thin and that the mean flow velocity exceeded larval swimming velocity approximately 5 mm (≈ 25 larval body lengths) from the panel surface.Therefore, we conclude that the scope for remote detection of waterborne cues is limited and that the likely explanation for the higher abundance of shipworm larvae associated with the wooden panels in the field is a response to a cue during or after attachment on, or very near, the substrate.

View Article: PubMed Central - PubMed

Affiliation: University of Gothenburg, Department of Biological and Environmental Sciences-Tjärnö, Strömstad, Sweden.

ABSTRACT
The life cycle of many sessile marine invertebrates includes a dispersive planktonic larval stage whose ability to find a suitable habitat in which to settle and transform into benthic adults is crucial to maximize fitness. To facilitate this process, invertebrate larvae commonly respond to habitat-related chemical cues to guide the search for an appropriate environment. Furthermore, small-scale hydrodynamic conditions affect dispersal of chemical cues, as well as swimming behavior of invertebrate larvae and encounter with potential habitats. Shipworms within the family Teredinidae are dependent on terrestrially derived wood in order to complete their life cycle, but very little is known about the cues and processes that promote settlement. We investigated the potential for remote detection of settling substrate via waterborne chemical cues in teredinid larvae through a combination of empirical field and laboratory flume experiments. Natural populations of teredinid larvae were significantly more abundant close to wooden structures enclosed in plankton net compared to empty control nets, clearly showing that shipworm larvae can sense and respond to chemical cues associated with suitable settling substrate in the field. However, the flume experiments, using ecologically relevant flow velocities, showed that the boundary layer around experimental wooden panels was thin and that the mean flow velocity exceeded larval swimming velocity approximately 5 mm (≈ 25 larval body lengths) from the panel surface. Therefore, we conclude that the scope for remote detection of waterborne cues is limited and that the likely explanation for the higher abundance of shipworm larvae associated with the wooden panels in the field is a response to a cue during or after attachment on, or very near, the substrate. Waterborne cues probably guide the larva in its decision to remain attached and settle, or to detach and continue swimming and drifting until the next encounter with a solid substrate.

No MeSH data available.


Related in: MedlinePlus

Field experiment.Experimental set up used to study detection of waterborne chemical cues by shipworm larvae in the field. Net bags with and without wooden panels were submerged at 1 m depth from a floating jetty. A vertical tow with a hoop-net (90 μm, illustrated by a grey triangle) was used to filter the water around the net bags. In each tow, the hoop-net including the net bag and its line was lifted to the surface.
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pone.0124950.g001: Field experiment.Experimental set up used to study detection of waterborne chemical cues by shipworm larvae in the field. Net bags with and without wooden panels were submerged at 1 m depth from a floating jetty. A vertical tow with a hoop-net (90 μm, illustrated by a grey triangle) was used to filter the water around the net bags. In each tow, the hoop-net including the net bag and its line was lifted to the surface.

Mentions: In order to investigate if shipworm larvae are able to detect suitable substrate via waterborne chemical cues under field conditions, 8 Norway spruce (Picea abies) panels (120 x 60 x 30 mm) were deployed at 1 m depth outside the SLCT in August 2011. The panels were placed in bags made from plankton net (50 μm) and attached to lines weighted down by brick stones (Fig 1). Control net bags, with similar shape but without wooden panels, were also prepared and weighted in the same way. Net bags with and without wooden panels were placed randomly with 3 m intervals from a dock. At two occasions (after 8 and 16 days), vertical tows were made using a hoop-net (90 μm) (Fig 1). Through this procedure, 192 L of water around each net bag was filtered. The hoop-net was thoroughly rinsed and collected larvae were fixed in ethanol (96%). The procedure was repeated in a random order for all net bags. Teredinid pediveliger larvae in the plankton samples were identified through their characteristic oval shape (i.e. greater height than length), yellowish color, and lack of "eyespot", which distinguish them from other bivalve larvae [38,39].


Natural populations of shipworm larvae are attracted to wood by waterborne chemical cues.

Toth GB, Larsson AI, Jonsson PR, Appelqvist C - PLoS ONE (2015)

Field experiment.Experimental set up used to study detection of waterborne chemical cues by shipworm larvae in the field. Net bags with and without wooden panels were submerged at 1 m depth from a floating jetty. A vertical tow with a hoop-net (90 μm, illustrated by a grey triangle) was used to filter the water around the net bags. In each tow, the hoop-net including the net bag and its line was lifted to the surface.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430175&req=5

pone.0124950.g001: Field experiment.Experimental set up used to study detection of waterborne chemical cues by shipworm larvae in the field. Net bags with and without wooden panels were submerged at 1 m depth from a floating jetty. A vertical tow with a hoop-net (90 μm, illustrated by a grey triangle) was used to filter the water around the net bags. In each tow, the hoop-net including the net bag and its line was lifted to the surface.
Mentions: In order to investigate if shipworm larvae are able to detect suitable substrate via waterborne chemical cues under field conditions, 8 Norway spruce (Picea abies) panels (120 x 60 x 30 mm) were deployed at 1 m depth outside the SLCT in August 2011. The panels were placed in bags made from plankton net (50 μm) and attached to lines weighted down by brick stones (Fig 1). Control net bags, with similar shape but without wooden panels, were also prepared and weighted in the same way. Net bags with and without wooden panels were placed randomly with 3 m intervals from a dock. At two occasions (after 8 and 16 days), vertical tows were made using a hoop-net (90 μm) (Fig 1). Through this procedure, 192 L of water around each net bag was filtered. The hoop-net was thoroughly rinsed and collected larvae were fixed in ethanol (96%). The procedure was repeated in a random order for all net bags. Teredinid pediveliger larvae in the plankton samples were identified through their characteristic oval shape (i.e. greater height than length), yellowish color, and lack of "eyespot", which distinguish them from other bivalve larvae [38,39].

Bottom Line: Natural populations of teredinid larvae were significantly more abundant close to wooden structures enclosed in plankton net compared to empty control nets, clearly showing that shipworm larvae can sense and respond to chemical cues associated with suitable settling substrate in the field.However, the flume experiments, using ecologically relevant flow velocities, showed that the boundary layer around experimental wooden panels was thin and that the mean flow velocity exceeded larval swimming velocity approximately 5 mm (≈ 25 larval body lengths) from the panel surface.Therefore, we conclude that the scope for remote detection of waterborne cues is limited and that the likely explanation for the higher abundance of shipworm larvae associated with the wooden panels in the field is a response to a cue during or after attachment on, or very near, the substrate.

View Article: PubMed Central - PubMed

Affiliation: University of Gothenburg, Department of Biological and Environmental Sciences-Tjärnö, Strömstad, Sweden.

ABSTRACT
The life cycle of many sessile marine invertebrates includes a dispersive planktonic larval stage whose ability to find a suitable habitat in which to settle and transform into benthic adults is crucial to maximize fitness. To facilitate this process, invertebrate larvae commonly respond to habitat-related chemical cues to guide the search for an appropriate environment. Furthermore, small-scale hydrodynamic conditions affect dispersal of chemical cues, as well as swimming behavior of invertebrate larvae and encounter with potential habitats. Shipworms within the family Teredinidae are dependent on terrestrially derived wood in order to complete their life cycle, but very little is known about the cues and processes that promote settlement. We investigated the potential for remote detection of settling substrate via waterborne chemical cues in teredinid larvae through a combination of empirical field and laboratory flume experiments. Natural populations of teredinid larvae were significantly more abundant close to wooden structures enclosed in plankton net compared to empty control nets, clearly showing that shipworm larvae can sense and respond to chemical cues associated with suitable settling substrate in the field. However, the flume experiments, using ecologically relevant flow velocities, showed that the boundary layer around experimental wooden panels was thin and that the mean flow velocity exceeded larval swimming velocity approximately 5 mm (≈ 25 larval body lengths) from the panel surface. Therefore, we conclude that the scope for remote detection of waterborne cues is limited and that the likely explanation for the higher abundance of shipworm larvae associated with the wooden panels in the field is a response to a cue during or after attachment on, or very near, the substrate. Waterborne cues probably guide the larva in its decision to remain attached and settle, or to detach and continue swimming and drifting until the next encounter with a solid substrate.

No MeSH data available.


Related in: MedlinePlus