Limits...
New Insights into Polychaete Traces and Fecal Pellets: Another Complex Ichnotaxon?

Kulkarni KG, Panchang R - PLoS ONE (2015)

Bottom Line: The study for the first time reports extensive fecal pellet production, distribution and their preservation as thick stacks in modern estuarine environment.Their occurrence as strings associated with mounds not only suggests pascichnial behaviour of polychaetes but also allows the assignment of post-Paleozoic Tomaculum to the activity of polychaete worms.The production of fecal pellets in such large quantities plays a major role in increasing the average grain size of the substrate of these estuarine tidal flats, thereby improving aeration within the substrate.

View Article: PubMed Central - PubMed

Affiliation: Biodiversity and Palaeobiology Group, Agharkar Research Institute (MACS-ARI), Pune, Maharashtra, India.

ABSTRACT
Neoichnological observations help refine paleoichnological records. The present study reports extensive observations on the distribution, morphology, occurrence and association of burrows and fecal pellets of the polychaete Nereis diversicolor in the Kundalika Estuary on the west coast of India. Our holistic study of these modern-day traces suggests it to be a complex trace arising from domichnial, fodinichnial and possibly pascichnial behavior of polychaetes. The study for the first time reports extensive fecal pellet production, distribution and their preservation as thick stacks in modern estuarine environment. These observations testify the fossilization potential of pellets and provide an explanation to their origin in the geological record. Their occurrence as strings associated with mounds not only suggests pascichnial behaviour of polychaetes but also allows the assignment of post-Paleozoic Tomaculum to the activity of polychaete worms. The production of fecal pellets in such large quantities plays a major role in increasing the average grain size of the substrate of these estuarine tidal flats, thereby improving aeration within the substrate.

No MeSH data available.


Related in: MedlinePlus

A. The shallow box core being extracted at Revdanda tidal flat. B & C. Field photographs of polychaete burrows associated with pellet mounds. The white arrows in C indicate pellet mounds. Innumerable pellets lie dispersed in the background on the surface of the mudflats. D. Wavy, sinuous and branched burrows of uniform width. Inset: pellet cluster. E. SEM photograph of a pellet aggregate. F & G. SEM images showing surficial striae on pellets. The pellet in F shows an attachment scar in negative relief. H. The undisturbed surface of the box core covered with randomly oriented pellets. Numerous cross-sections of pellets directed towards the reader show dark, homogenous internal structure of pellets. I. One of the several strings of fecal pellets connecting two pellet mounds. J. Lateral surface of box core showing stacked laminae of pellets.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4595207&req=5

pone.0139933.g002: A. The shallow box core being extracted at Revdanda tidal flat. B & C. Field photographs of polychaete burrows associated with pellet mounds. The white arrows in C indicate pellet mounds. Innumerable pellets lie dispersed in the background on the surface of the mudflats. D. Wavy, sinuous and branched burrows of uniform width. Inset: pellet cluster. E. SEM photograph of a pellet aggregate. F & G. SEM images showing surficial striae on pellets. The pellet in F shows an attachment scar in negative relief. H. The undisturbed surface of the box core covered with randomly oriented pellets. Numerous cross-sections of pellets directed towards the reader show dark, homogenous internal structure of pellets. I. One of the several strings of fecal pellets connecting two pellet mounds. J. Lateral surface of box core showing stacked laminae of pellets.

Mentions: Undisturbed sediment cores, both circular (length 1 m; diameter 11.5 cm) and box-shaped (20 x 18 x 22 cm3) (Fig 2A), were extracted from the tidal flats for laboratory studies. The cores were cut open after a week or two, after little desiccation, to enable observations. The dried sediment cores and pellets were observed under the microscope. Scanning Electron Microscopic (SEM) imaging of pellets was done on a Zeiss EVO MA 15 machine in order to describe their surface ultrastructure.


New Insights into Polychaete Traces and Fecal Pellets: Another Complex Ichnotaxon?

Kulkarni KG, Panchang R - PLoS ONE (2015)

A. The shallow box core being extracted at Revdanda tidal flat. B & C. Field photographs of polychaete burrows associated with pellet mounds. The white arrows in C indicate pellet mounds. Innumerable pellets lie dispersed in the background on the surface of the mudflats. D. Wavy, sinuous and branched burrows of uniform width. Inset: pellet cluster. E. SEM photograph of a pellet aggregate. F & G. SEM images showing surficial striae on pellets. The pellet in F shows an attachment scar in negative relief. H. The undisturbed surface of the box core covered with randomly oriented pellets. Numerous cross-sections of pellets directed towards the reader show dark, homogenous internal structure of pellets. I. One of the several strings of fecal pellets connecting two pellet mounds. J. Lateral surface of box core showing stacked laminae of pellets.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595207&req=5

pone.0139933.g002: A. The shallow box core being extracted at Revdanda tidal flat. B & C. Field photographs of polychaete burrows associated with pellet mounds. The white arrows in C indicate pellet mounds. Innumerable pellets lie dispersed in the background on the surface of the mudflats. D. Wavy, sinuous and branched burrows of uniform width. Inset: pellet cluster. E. SEM photograph of a pellet aggregate. F & G. SEM images showing surficial striae on pellets. The pellet in F shows an attachment scar in negative relief. H. The undisturbed surface of the box core covered with randomly oriented pellets. Numerous cross-sections of pellets directed towards the reader show dark, homogenous internal structure of pellets. I. One of the several strings of fecal pellets connecting two pellet mounds. J. Lateral surface of box core showing stacked laminae of pellets.
Mentions: Undisturbed sediment cores, both circular (length 1 m; diameter 11.5 cm) and box-shaped (20 x 18 x 22 cm3) (Fig 2A), were extracted from the tidal flats for laboratory studies. The cores were cut open after a week or two, after little desiccation, to enable observations. The dried sediment cores and pellets were observed under the microscope. Scanning Electron Microscopic (SEM) imaging of pellets was done on a Zeiss EVO MA 15 machine in order to describe their surface ultrastructure.

Bottom Line: The study for the first time reports extensive fecal pellet production, distribution and their preservation as thick stacks in modern estuarine environment.Their occurrence as strings associated with mounds not only suggests pascichnial behaviour of polychaetes but also allows the assignment of post-Paleozoic Tomaculum to the activity of polychaete worms.The production of fecal pellets in such large quantities plays a major role in increasing the average grain size of the substrate of these estuarine tidal flats, thereby improving aeration within the substrate.

View Article: PubMed Central - PubMed

Affiliation: Biodiversity and Palaeobiology Group, Agharkar Research Institute (MACS-ARI), Pune, Maharashtra, India.

ABSTRACT
Neoichnological observations help refine paleoichnological records. The present study reports extensive observations on the distribution, morphology, occurrence and association of burrows and fecal pellets of the polychaete Nereis diversicolor in the Kundalika Estuary on the west coast of India. Our holistic study of these modern-day traces suggests it to be a complex trace arising from domichnial, fodinichnial and possibly pascichnial behavior of polychaetes. The study for the first time reports extensive fecal pellet production, distribution and their preservation as thick stacks in modern estuarine environment. These observations testify the fossilization potential of pellets and provide an explanation to their origin in the geological record. Their occurrence as strings associated with mounds not only suggests pascichnial behaviour of polychaetes but also allows the assignment of post-Paleozoic Tomaculum to the activity of polychaete worms. The production of fecal pellets in such large quantities plays a major role in increasing the average grain size of the substrate of these estuarine tidal flats, thereby improving aeration within the substrate.

No MeSH data available.


Related in: MedlinePlus