Bathymetric and seasonal changes in photosynthesis and respiration of the phototrophic sponge Phyllospongia lamellosa in comparison with respiration by the heterotrophic sponge Ianthella basta on Davies Reef, Great Barrier Reef

1997 ◽  
Vol 48 (7) ◽  
pp. 589 ◽  
Author(s):  
Anthony C. Cheshire ◽  
Clive R. Wilkinson ◽  
Stephanie Seddon ◽  
Grant Westphalen
Keyword(s):  
Light Intensity ◽  
Great Barrier Reef ◽  
Respiration Rate ◽  
Seasonal Changes ◽  
Shallow Waters ◽  
Barrier Reef ◽  
Fresh Weight ◽  
Respiration Rates ◽  
Reduced Light ◽  
Photosynthesis And Respiration

The phototrophic sponge Phyllospongia lamellosa is found to depths of 30 m on Davies Reef. Studies of the photophysiology show that this corresponds to the depth at which the sponge–symbiont system can meet 80% of its daily respiratory carbon needs photosynthetically. Net 24-h production was constant to a depth of 20 m (20 µmol O2 g-1 fresh weight day -1 ) and then decreased to compensatory levels at 25 m. The maintenance of net 24-h production to a depth of 20 m was characterized by reductions in the sub-saturating light intensity (Ik ), indicating increased efficiency of light usage at depth. At depths greater than 20 m the changes in Ik could not compensate for the reduced light intensity. The respiration rate of Phyllospongia (3–5 µmol O2 g-1 fresh weight h-1 ) was significantly greater than that of the heterotrophic sponge Ianthella (2.0–3.6 µmol O2 g-1 fresh weight h-1 ) to an extent that depended on season and location. Respiration rates for both species changed similarly between seasons, being higher in summer. There was no evidence for increased respiration rates in shallower water (<10 m), suggesting that this is not a cause for the reduced occurrence of Phyllospongia in shallow waters.

scholarly journals Respiration characteristics and its responses to hydrothermal seasonal changes in reconstructed soils

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Na Lei ◽  
Juan Li ◽  
Tianqing Chen
Keyword(s):  
Soil Respiration ◽  
Water Content ◽  
Respiration Rate ◽  
Exponential Function ◽  
Seasonal Changes ◽  
Volumetric Water Content ◽  
Heterotrophic Respiration ◽  
Autotrophic Respiration ◽  
Monthly Average ◽  
Respiration Rates

AbstractSeasonal changes in respiration and the components of four reconstructed soils (gravel + meteorite + lou; gravel + shale + lou; gravel + sand + lou; and gravel + soft rock + lou) in barren gravel land were monitored using the soil carbon flux measurement system. The results showed that (1) the monthly average respiration rate and the rates of the components in the four reconstructed soils were the highest in summer and lowest in winter. In winter, the monthly average respiration rates of the four reconstructed soils were not different (p > 0.05). In summer, the monthly average respiration rate of the sand or meteorite reconstructed soil was different from that of the other three (p < 0.05). (2) The heterotrophic and autotrophic respiration rates were different between the four reconstructed soils (p < 0.05). The contribution of heterotrophic respiration to total respiration in the four reconstructed soils was greater than that of autotrophic respiration throughout the year. In winter, autotrophic respiration accounts for the smallest proportion of total respiration. As the temperature rises, the proportion of autotrophic respiration to total respiration gradually increases and peaks in summer. In summer, the proportion of heterotrophic respiration in the total respiration is the smallest. With the decrease in temperature, the proportion of heterotrophic respiration in total respiration gradually increases and peaks in winter. (3) The maximum and minimum values of the monthly average respiration rate of the four reconstructed soils coincided with the months of maximum and minimum soil temperature. The soil volumetric water content changed with the amount of precipitation. The correlation between soil respiration and temperature was greater than that between soil respiration and volumetric water content. (4) The correlation in seasonal variation between respiration of the four remodelled soils and hydrothermal factors in the study area can be characterised by an exponential function and power-exponential function.

The identity of two species of cyphonautes larvae (Bryozoa: Cheilostomata) from Lizard Island, Great Barrier Reef, Australia

2001 ◽  
Vol 81 (6) ◽  
pp. 995-999 ◽  
Author(s):  
P.J. Hayward
Keyword(s):  
Great Barrier Reef ◽  
The Other ◽  
Shallow Waters ◽  
Barrier Reef ◽  
Unknown Species ◽  
Lizard Island

Two species of bryozoan cyphonautes larvae are described and illustrated from plankton tows made among coral heads in shallow waters at Lizard Island, Great Barrier Reef, Australia. Individuals of both species settled and metamorphosed, and their ancestrulae and early astogeny are also described and illustrated. One is recognized as a formerly unknown species of Conopeum, C. ponticum sp. nov., the other is attributed to Biflustra reticulata.

Hooking mortality of two species of shallow-water reef fish caught by recreational angling methods

1997 ◽  
Vol 48 (6) ◽  
pp. 479 ◽  
Author(s):  
B. K. Diggles ◽  
I. Ernst
Keyword(s):  
Great Barrier Reef ◽  
Total Mortality ◽  
Handling Time ◽  
Body Cavity ◽  
Shallow Waters ◽  
Barrier Reef ◽  
Fish Size ◽  
Recreational Angling ◽  
Lutjanus Carponotatus ◽  
Observation Period

The hooking mortality of two teleosts, the yellow stripey Lutjanus carponotatus (Lutjanidae), and the wire netting cod Epinephelus quoyanus (Serranidae), was examined for fish captured with lures and bait from shallow waters (<2 m) on the Great Barrier Reef. Total mortality for both species (n = 340 fish) over the 48-h observation period was low (1.76%). Baitfishing with single hooks caused a significantly higher post-release mortality rate (5.1%) than did lure fishing with treble or single hooks (0.4%), and was the hooking method most likely to cause bleeding and damage to vital organs. Death of fish was observed only in instances where hooks penetrated the pericardium or body cavity. Handling time was significantly affected by fish size and hooking location, did not vary significantly between fish species, and was significantly reduced when barbless hooks were used in both lure and baitfishing. One specimen of each species, deeply hooked in the gut or oesophagus while baitfishing, was allowed to retain the hook; both fish survived and subsequently regurgitated the hook during the observation period. The relevance of these data to management of line fisheries on the Great Barrier Reef is discussed.

scholarly journals Seasonal Changes and Cultivar Difference in Turf Quality, Photosynthesis, and Respiration of Creeping Bentgrass

HortScience ◽  
2001 ◽  
Vol 36 (6) ◽  
pp. 1131-1135 ◽  
Author(s):  
Xiaozhong Liu ◽  
Bingru Huang
Keyword(s):  
Respiration Rate ◽  
Photosynthetic Rate ◽  
Seasonal Changes ◽  
Photochemical Efficiency ◽  
Creeping Bentgrass ◽  
Turf Quality ◽  
Putting Green ◽  
Summer Decline ◽  
Plant Respiration ◽  
Photosynthesis And Respiration

Summer decline in turf quality of creeping bentgrass (Agrostis palustris Hud.) is a major problem in golf course green management. The objective of this study was to examine whether seasonal changes and cultivar variations in turf performance are associated with changes in photosynthesis and respiration rates for creeping bentgrass. The study was conducted on a USGA-specification putting green in Manhattan, Kans., during 1997 and 1998. Four creeping bentgrass cultivars, `L-93', `Crenshaw', `Penncross', and `Providence', were examined. Grasses were mowed daily at 4 mm and irrigated on alternate days to replace 100% of daily water loss. In both years, turf quality, canopy net photosynthetic rate (Pn), and leaf photochemical efficiency (Fv/Fm) were high in May and June and decreased to the lowest levels in July through September. Whole-plant respiration rate (R) and canopy minus air temperature (▵T) increased during summer months. In October, turf quality and Pn increased, whereas R and T decreased. During summer months, turf quality was highest for `L-93', lowest for `Penncross', and intermediate for `Providence' and `Crenshaw'. Seasonal changes and cultivar variations in turf quality were associated with the decreasing photosynthetic rate and increasing respiration rate.

scholarly journals Helmutneris vadum, a new species of Lumbrineridae (Annelida) from Lizard Island, Great Barrier Reef, Australia

Zootaxa ◽  
2020 ◽  
Vol 4877 (3) ◽  
pp. 413-421
Author(s):  
POLINA BORISOVA ◽  
NATALIYA BUDAEVA
Keyword(s):  
New Species ◽  
Great Barrier Reef ◽  
16S Rdna ◽  
Shallow Waters ◽  
Barrier Reef ◽  
Lizard Island ◽  
A New Species

A new species of Lumbrineridae, Helmutneris vadum n. sp., is described from shallow waters near Lizard Island, Great Barrier Reef, Queensland, Australia. The new species differs from two other known species of Helmutneris by having bidentate maxillae III and no ventral limbate chaetae. Sequences of the fragments of COI and 16S rDNA for two specimens including the holotype are deposited in GenBank. A key for three species of Helmutneris known to date is provided.

Influence of environmental factors on respiration of excised tissues of American oysters, Crassostrea virginica (Gmelin)

1971 ◽  
Vol 49 (3) ◽  
pp. 353-360 ◽  
Author(s):  
J. A. Percy ◽  
F. A. Aldrich ◽  
T. R. Marcus
Keyword(s):  
Environmental Factors ◽  
Crassostrea Virginica ◽  
Respiration Rate ◽  
Seasonal Changes ◽  
Adductor Muscle ◽  
American Oyster ◽  
Respiration Rates ◽  
Excised Tissues ◽  
Seawater Medium

Respiration rates of excised gill, mantle, and adductor muscle of the American oyster, Crassostrea virginica (Gmelin), were measured by the Warburg technique at a number of temperatures and salinities and at various times during the year. Dilution of the seawater medium stimulates gill respiration, has no significant effect on mantle respiration and inhibits adductor muscle respiration. Rate–temperature curves are presented for all three tissues. Respiration rates of gill and mantle declined by about 17% in the autumn, while adductor muscle respiration increased by about 14%. A number of possible explanations for the seasonal changes are discussed.

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