Deposit Feeding During Tidal Emersion by the Suspension-feeding Polychaete, Mesochaetopterus taylori

2007 ◽  
Vol 6 (2) ◽  
pp. 351-358 ◽  
Author(s):  
Thomas O. Busby ◽  
Craig J. Plante
Author(s):  
John K. Keogh ◽  
Brendan F. Keegan

Morphological study of the podia of the suspension feeding Amphiura filiformis and the deposit feeding Amphiura chiajei revealed sensory–secretory complexes in the podial epidermis, consisting of four cells, two secretory and two sensory. Large mucus cells were found in association, but not exclusively, with the sensory–secretory complexes. In A. filiformis, mucus cells stained positively for both acid and neutral mucopolysaccharides, while, in A. chiajei, these cells stained only for acid mucopolysaccharides. The surfaces of the arm podia in A. chiajei were relatively smooth, while the arm podia of A. filiformis bear papillae. The sensory–secretory complexes open through numerous paired pores, with each pair having an intervening cilium. Pores were restricted to the podial tip in A. chiajei, while in A. filiformis they are concentrated on the podial tip and on the papillae. Amphiura chiajei shows very little differentiation of the podia along the length of the arm. In A. filiformis, the distal podia have papillae throughout their entire length, with pores being found on the head region and the papillar tips. Here, the papillae are oriented in such a way (i.e. facing inward towards the ventral arm plate) as to increase the area of the filtering surface of the podium, serviced by the sticky secretions from the sensory–secretory complexes. The proximal podia are relatively simple in structure and are thought to function more in the transportation of mucus wrapped particles to the mouth rather than in their capture. The difference in structure of the podia and chemical composition of podial secretory cells are taken to reflect the difference in feeding styles of the two species.


Author(s):  
J. Douglas McKenzie ◽  
B. E. Picton

Conflicting opinions exist as to the method of feeding employed by Leptopentacta elongata (Dub. and Kor). Orton (1914) and Mortensen (1927) suggested that it may be a deposit feeder. Chia & Buchanan (1969) noted that post larval specimens up to 1 year old deposit fed. Fankboner (1981), in a short study, concluded that the adults were cryptic deposit feeders. Hunt (1925) and Fish (1967), however, observed what they concluded was suspension feeding. All the above observations were the result of aquarium studies. Fish (1967) also demonstrated that Leptopentacta hibernated between October and April or May both in the field and in aquarium. He also observed that hibernation could be induced in the summer months by reducing water temperature to 8°C but that winter hibernation could not be curtailed by raising the water temperature.Obsevations made by one of us (B.P.) while diving indicate that Leptopentacta suspension feeds. This behaviour has been observed on several occasions from several sites around the Irish coastline with specimens then being caught and their identity confirmed. While feeding the tentacles are held clear of the substrate to intercept suspended material.These observations clearly do not support the description of Leptopentacta solely as a cryptic deposit feeder, indeed the evidence for the adults deposit feeding at all is weak. Orton (1914) and Mortensen were only speculating on Leptopentacta being a deposit feeder based on the observation that specimens in aquaria spent much of their time completely buried. Hibernation, as shown by Fish (1967), is a possible explanation for this.


2013 ◽  
Vol 132 (1) ◽  
pp. 62-68 ◽  
Author(s):  
William. B. Jaeckle ◽  
Richard. R. Strathmann

2020 ◽  
Vol 78 (3) ◽  
pp. 169-195
Author(s):  
Donald C. Rhoads ◽  
David K. Young

Deposit-feeding and suspension-feeding benthos in Buzzards Bay, Massachusetts, show marked spatial separation; suspension feeders are largely confined to sandy or firm mud bottoms while deposit feeders attain high densities on soft muddy substrata. Food source and bottom stability have been investigated as potential factors effecting this trophic-group separation. Between October 4, 1967 and August 22, 1969, observations were made at 11 stations in Buzzards Bay, Massachusetts, along two widely separated transects over bottoms ranging in texture from silt to fine and medium sand. Water depths at these stations ranged from 3 m to 20 m. Scuba divers made many of the field observations and collected most of the samples. This study included sampling of benthic macrofauna, taking bottom photographs, analyzing sedimentary structures, texture, organic content and water content of the sediments, and measuring both water currents and suspended sediment above the bottom. Laboratory experiments were also carried out to determine differential resuspension between burrowed and unburrowed muds. Intensive reworking of the upper few centimeters of a mud bottom by deposit feeders produces a fluid fecal-rich surface that is easily resuspended by low-velocity tidal currents. We suggest that the physical instability of this fecal surface tends to: (i) clog the filtering structures of suspension-feeding organisms, (ii) bury newly settled larvae or discourage the settling of suspension-feeding larvae, and (iii) prevent sessile epifauna from attaching to an unstable mud bottom. Thus suspension feeders are unable to successfully populate all areas of the bottom where a suspended food source is available, especially in areas where mud bottoms are intensively reworked by deposit feeders. Modification of the benthic environment by deposit feeders, resulting in the exclusion of many suspension feeders and sessile epifauna, is an example of trophic group amensalism. This biotic relationship appears to be important in shaping trophic-group distributions in embayments and basins on continental shelves.


2019 ◽  
Author(s):  
Shang-Shu Shih ◽  
Tzung-Su Ding ◽  
Chang-Po Chen ◽  
Shou-Chung Huang ◽  
Hwey-Lian Hsieh

AbstractMangrove expansion monopolizes estuarine landscapes by diminishing habitat diversity and hence biodiversity. Physical landcover types, including mangrove vegetation, influence polychaete and avifauna habitat uses. The connections between the physical to biota-associated landscapes warrant investigation. We determine how to best describe the landscape in a mangrove-vegetated wetland according to the physical, polychaete and bird domains and identify what physical attributes would affect the biota-associated landscapes. Differences among the physical and biota-associated landscapes were evaluated using multivariate ordination analyses. Six physical landcover types were aligned along elevation, inundation and sedimentary gradients. The polychaete-associated landscape was structured by three landcover types, mainly mangroves and tidal flats with intermediate and high inundation. Deposit-feeding spionid and nereid, carnivorous goniadid and suspension-feeding sabellid polychaetes depended on the different landcover types. Shorebirds occurred distinctively in tidal flats with large, open surface areas. Egrets characterized tidal flats and mangroves, and foliage and ground gleaners characterized mangroves. Open tidal flats are crucial to polychaetes, which are the main prey of shorebirds and are also important to egret foraging. Our results suggest that effective management strategies for conserving these migratory birds require the maintenance of open tidal flats in the landscape.


1986 ◽  
Vol 64 (9) ◽  
pp. 2068-2071 ◽  
Author(s):  
George L. Shinn

Egg capsules of Fallacophospes inchoatus are roughly tetrahedral in shape, have a hydratable adhesive covering, and typically contain two zygotes and 40–50 yolk cells. Embryos complete development in 40–42 days and hatch spontaneously when kept in seawater at 8–10 ° C. This observation suggests that the suspension-feeding crinoid hosts are infected by eating free-swimming larvae rather than by eating egg capsules that contain embryos, which is the case for deposit-feeding echinoderms that harbour umagillids. The possibility is raised that umagillids originally evolved as parasites of suspension-feeding echinoderms and that the mode of reproduction of crinoid-inhabiting umagillids is primitive for the family.


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