In situ pumping activities of tropical Demospongiae

Reiswig, Henry M.

doi:10.1007/bf00348816

Cited by 280 publications

(288 citation statements)

References 20 publications

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“…Despite the lack of a nervous system, sponges appear to be no different, having the capacity to detect light (e.g., Leys and Degnan, 2001;Elliott et al, 2004;Rivera et al, 2012) and to display diurnal physiological and reproductive patterns (Reiswig, 1971;Amano, 1988;Nickel, 2004) consistent with possessing a circadian clock. Here we ask which genes that contribute to the regulation of circadian rhythms in other animals are present in the genome of the demosponge A. queenslandica, and whether any of these genes are expressed in patterns consistent with a circadian role in this early-diverging animal lineage.…”

Section: Discussionmentioning

confidence: 99%

Origin of the Animal Circadian Clock: Diurnal and Light-Entrained Gene Expression in the Sponge Amphimedon queenslandica

et al. 2017

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The circadian clock is a molecular network that coordinates organismal behavior and physiology with daily environmental changes in the day-night cycle. In eumetazoans (bilaterians + cnidarians), this network appears to be largely conserved, yet different from other known eukaryotic circadian networks. To determine if the eumetazoan circadian network has an older origin, we ask here whether orthologs comprising this network are expressed in a manner consistent with a role in regulating circadian patterns in a representative of an earlier-branching animal lineage, the sponge Amphimedon queenslandica. The A. queenslandica genome encodes orthologs of many eumetazoan circadian genes, including two cryptochrome genes that encode flavoproteins, three Timeout genes, and two PAR-bZIP and seven bHLH-PAS transcription factor genes.There is no apparent Cycle ortholog, although we can identify three closely related ARNT genes. Of the putative circadian genes, only AqPARa and AqCry2 have a consistent oscillating diurnal expression profile, and the rhythmic expression of both these genes is partially lost when the animals are exposed to constant light or darkness. Expression of the other putative circadian genes, in particular AqClock, is neither diurnally-oscillating nor light-dependent. AqPARa and AqCry2 are also temporally and spatially co-expressed throughout embryonic and larval development. Transcripts of these genes are enriched first in cells comprising the larval posterior pigment ring, which is a simple photosensory organ that is responsible for the negative phototactic behavior displayed by larvae, and subsequently in the larval epithelial and subepithelial layers. The combined findings of no clear Cycle ortholog and of PAR-bZIP and cryptochrome being the only orthologs expressed in a pattern consistent with a circadian role suggests that either (i) the ancestral metazoan circadian network was simpler than the eumetazoan network, or (ii) that this sponge has lost some components, as has occurred in some other animals such as Hydra.

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Section: Discussionmentioning

confidence: 99%

Origin of the Animal Circadian Clock: Diurnal and Light-Entrained Gene Expression in the Sponge Amphimedon queenslandica

et al. 2017

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“…Being passive filter feeders using an elaborate skeletal sieve system, ajacicyathides could presumably pump at fairly low exhalant and inhalant velocities. Consideration of similar Recent sponges (reisWig, 1971) shows that such forms were resistant to the occlusion of their incurrent system. Among the Archaeocyathida, the sealing of all basal ostia by secondary skeleton was also a response to high sedimentation rates in order to prevent sediment infiltration into the choanoderm (Debrenne & ZhurAvlev, 1992b, p. 62;KrAuTTer, 1994).…”

Section: Archaeocyathan Interactionsmentioning

confidence: 99%

Treatise Online, no. 38: Part E, Revised, Volume 4, Chapter 18: General features of the Archaeocyatha

Debrenne¹,

Zhuravlev²,

Kruse³

2012

TREON

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“…The principle of operation is based on the rate of heat removed from a submerged, electrically heated thermistor (temperature sensitive electrical resistor), which is related to the speed of the water mass moving past it (Reiswig 1971(Reiswig , 1974Vogel 1977). The nondirectional flow probe comprised a 0.9-mm diameter glass bead-covered thermistor silicone sealed onto the distal end of a 2-mm diameter stainless steel tube.…”

Section: Thermistor Flow Sensor and Recordermentioning

confidence: 99%

Environmental Flow Regimes for Dysidea avara Sponges

et al. 2008

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The aim of our research is to design tank systems to culture Dysidea avara for the production of avarol. Flow information was needed to design culture tanks suitable for effective production. Water flow regimes were characterized over a 1-year period for a shallow rocky sublittoral environment in the Northwestern Mediterranean where D. avara sponges are particularly abundant. Three-dimensional Doppler current velocities at 8-10-m depths ranged from 5 to 15 cm/s over most seasons, occasionally spiking to 30-66 cm/s. A thermistor flow sensor was used to map flow fields in close proximity (≈2 cm) to individual sponges at 4.5-, 8.8-, and 14.3-m depths. These "proximal flows" averaged 1.6 cm/s in calm seas and 5.9 cm/s during a storm, when the highest proximal flow (32.9 cm/s) was recorded next to a sponge at the shallowest station. Proximal flows diminished exponentially with depth, averaging 2.6 cm/s± 0.15 SE over the entire study. Flow visualization studies showed that oscillatory flow (0.20-0.33 Hz) was the most common regime around individual sponges. Sponges at the 4.5-m site maintained a compact morphology with large oscula year-around despite only seasonally high flows. Sponges at 8.8 m were more erect with large oscula on tall protuberances. At the lowest-flow 14.3-m site, sponges were more branched and heavily conulated, with small oscula. The relationship between sponge morphology and ambient flow regime is discussed.

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In situ pumping activities of tropical Demospongiae

Cited by 280 publications

References 20 publications

Origin of the Animal Circadian Clock: Diurnal and Light-Entrained Gene Expression in the Sponge Amphimedon queenslandica

Origin of the Animal Circadian Clock: Diurnal and Light-Entrained Gene Expression in the Sponge Amphimedon queenslandica

Treatise Online, no. 38: Part E, Revised, Volume 4, Chapter 18: General features of the Archaeocyatha

Environmental Flow Regimes for Dysidea avara Sponges

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