Role of particle wettability in capture by a suspension-feeding crab ( Emerita talpoida )

1999 ◽  
Vol 133 (3) ◽  
pp. 419-428 ◽  
Author(s):  
S. Conova
Author(s):  
Peter G. Beninger ◽  
Marcel Le Pennec

Histochemical techniques were used to investigate the possible role of the buccooesophageal glands in the blue mussel, Mytilus edulis L. (Mollusca: Bivalvia). No activity was observed for any of the eight major digestive enzymes tested; however, the glands contained large amounts of both neutral and acid mucopolysaccharides. These results confirm the importance of mucus in the ingestive process in M. edulis, and do not support the hypothesis of ingestion of particles suspended in water alone.Until recently it was thought that the Bivalvia were the only class of molluscs in which some type of secretory gland of extracellular digestive function in the bucco-oesophageal region was totally absent (Table 1). However, in a study of the mode of particle ingestion in five species of suspension-feeding bivalves, an extensive glandular complex was reported in the bucco-oesophageal region of Mytilus edulis L. only (Beninger et al., 1991). Although these glands were observed to liberate secretions into the oesophageal lumen, it was not known whether they performed any digestive function.


2020 ◽  
Vol 6 (49) ◽  
pp. eabc6721
Author(s):  
John R. Paterson ◽  
Gregory D. Edgecombe ◽  
Diego C. García-Bellido

Radiodonts are nektonic stem-group euarthropods that played various trophic roles in Paleozoic marine ecosystems, but information on their vision is limited. Optical details exist only in one species from the Cambrian Emu Bay Shale of Australia, here assigned to Anomalocaris aff. canadensis. We identify another type of radiodont compound eye from this deposit, belonging to ‘Anomalocaris’ briggsi. This ≤4-cm sessile eye has >13,000 lenses and a dorsally oriented acute zone. In both taxa, lenses were added marginally and increased in size and number throughout development, as in many crown-group euarthropods. Both species’ eyes conform to their inferred lifestyles: The macrophagous predator A. aff. canadensis has acute stalked eyes (>24,000 lenses each) adapted for hunting in well-lit waters, whereas the suspension-feeding ‘A.’ briggsi could detect plankton in dim down-welling light. Radiodont eyes further demonstrate the group’s anatomical and ecological diversity and reinforce the crucial role of vision in early animal ecosystems.


2021 ◽  
Vol 15 (2) ◽  
pp. 153
Author(s):  
Marcello Guimarães Simões ◽  
Antonio Carlos Marques ◽  
Luiz Henrique Cruz de Mello ◽  
Renato Pirani Ghilardi

The Megadesmidae (Bivalvia, Anomalodesmata) fossil record was examined in order to assess the role of taphonomy in cladistic analysis. Megadesmids are thick-shelled, infaunal, suspension-feeding bivalves. Our data indicate that their fossil record seems biased in favor of thick-shelled, shallow-burrowing genera and/or deep­burrowing forms. Consequently, there is a relation between the mode of life (shallow versus deep) and the resolution and quality of the fossil record. Deep-burrowers (Vacunella) are often preserved in life position offering a more accurate (temporal and spatial) fossil record, adequate for paleoecological inferences, while shallow-burrower shells (Plesiocyprinella), that are more prone to post-mortem transport and temporal mixing, offer a record with poor spatial and temporal resolution. The identification of homoplasy among infauna! bivalves constitutes a major challenge for their cladistic analysis. Within Megadesmidae intrinsic (bauplan limitations) and extrinsic (better preservational potential) factors favor the occurrence and preservation of homoplasy among the deep-burrowers. The implications are: a) clustering of deep-burrowing bivalves (Vacunella, Roxoa) due to parallel homoplasies, forming "adaptive", not necessarily "evolutive" taxa, and b) lower consistency indices in their cladistic analysis. 


1988 ◽  
Vol 45 (6) ◽  
pp. 1069-1074 ◽  
Author(s):  
Charles H. Greene ◽  
Michael R. Landry

Carnivorous suspension feeding is described for the large subarctic calanoid copepod Neocalanus cristatus. This foraging mode relies on the use of a feeding current to entrain potential prey items and transport them into the copepod's capture area. The extensive use of a feeding current to entrain and transport prey into the capture area distinguishes carnivorous suspension feeding from the predatory modes typically described for other calanoid copepods. The consequences of carnivorous suspension feeding on N. cristatus' prey-selection patterns are significant. Feeding experiments reveal that the vulnerability of naupliar prey declines with increasing prey size, just the opposite result observed for other marine calanoids exhibiting more typical predatory feeding modes. The role of omnivorous feeding by N. cristatus within the pelagic ecosystem of the subarctic Pacific is also discussed. In contrast with earlier hypotheses, the results reported here are consistent with the emerging view that this large suspension-feeding copepod may be having at least as great an impact on the microzooplankton as on the phytoplankton of the region.


2015 ◽  
Vol 229 (3) ◽  
pp. 289-298 ◽  
Author(s):  
Jan A. Pechenik ◽  
Casey M. Diederich ◽  
Oscar R. Chaparro ◽  
Victor M. Cubillos ◽  
Daniela A. Mardones-Toledo

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