scholarly journals Stable isotopes reveal limitations in C and N assimilation in the Caribbean reef corals Madracis auretenra, M. carmabi and M. formosa

2010 ◽  
Vol 412 ◽  
pp. 103-112 ◽  
Author(s):  
C Maier ◽  
MG Weinbauer ◽  
J Pätzold
1992 ◽  
Vol 66 (4) ◽  
pp. 570-594 ◽  
Author(s):  
Ann F. Budd ◽  
Thomas A. Stemann ◽  
Robert H. Stewart

Forty-three species of 25 genera are described in a collection of 170 large, massive reef corals from the upper Eocene Gatuncillo Formation near Lago Alahuela in central Panama. Comparisons with type material for other Eocene Caribbean reef corals suggest that 27 of these species are new. Twenty-four of these species are named herein. Like other Eocene Caribbean reef-coral faunas, the fauna is rich in Astrocoenia, Actinacis, and Astreopora; however, unlike other faunas, plocoid and meandroid members of the family Faviidae (e.g., Montastraea, Agathiphyllia, Goniastrea, and Colpophyllia) are abundant. Also present are the oldest known representatives of the genera Meandrina, Coscinaraea, Alveopora, Heliopora, and Pocillopora, as well as the only recorded occurrences of Coscinaraea and Cyathoseris from the Caribbean. Comparisons with Oligocene and Recent Caribbean reef-coral faunas suggest that the generic composition of Cenozoic Caribbean reefs became established during the Eocene. With exception of the family Mussidae, much of the post-Oligocene history of the Caribbean is one of extinction at the generic level (19 of the 28 Eocene genera became extinct) and proliferation of species within the surviving genera.


1994 ◽  
Vol 68 (5) ◽  
pp. 951-977 ◽  
Author(s):  
Ann F. Budd ◽  
Thomas A. Stemann ◽  
Kenneth G. Johnson

To document evolutionary patterns in late Cenozoic Caribbean reef corals, we compiled composite stratigraphic ranges of 49 genera and 175 species using Neogene occurrences in the Cibao Valley sequence of the northern Dominican Republic and faunal lists for 24 Miocene to Recent sites across the Caribbean region. This new compilation benefits in particular from increased sampling at late Miocene to early Pleistocene sites and from increased resolution and greater taxonomic consistency provided by the use of morphometric procedures in species recognition.Preliminary examination and quantitative analysis of origination and extinction patterns suggest that a major episode of turnover took place between 4 and 1 Ma during Plio-Pleistocene time. During the episode, extinctions were approximately simultaneous in species of all reef-building families, except the Mussidae. Most strongly affected were the Pocilloporidae (Stylophora and Pocillopora), Agariciidae (Pavona and Gardineroseris), and free-living members of the Faviidae and Meandrinidae. At the genus level, mono- and paucispecific as well as more speciose genera became regionally extinct. Many of the extinct genera live today in the Indo-Pacific region, and some are important components of modern eastern Pacific reefs. Global extinctions were concentrated in free-living genera. During the turnover episode, no new genera or higher taxa arose. Instead, new species originated within the surviving Caribbean genera at approximately the same time as the extinctions, including many dominant modern Caribbean reef-building corals (e.g., Acropora palmata and the Montastraea annularis complex).Excluding this episode, the taxonomic composition of the Caribbean reef-coral fauna remained relatively unchanged during the Neogene. Minor exceptions include: 1) high originations in the Agariciidae and free-living corals during late Miocene time; and 2) regional or global extinctions of several important Oligocene Caribbean reef builders during early to middle Miocene time.


2006 ◽  
Vol 86 (6) ◽  
pp. 1443-1447 ◽  
Author(s):  
D. Fourgon ◽  
G. Lepoint ◽  
I. Eeckhaut

Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiuroids, Ophiomastix venosa and Ophiocoma scolopendrina, and to assess the potential benefit obtained by the symbiotic Ophiomastix venosa juveniles. A tracer experiment was also carried out to clarify the contribution of algae to the nitrogen uptake amongst the tested ophiuroids. Our results suggest that Ophiocoma scolopendrina adults occupy a higher position in the food web than Ophiomastix venosa and mainly feed on neuston. In contrast, O. venosa adults feed on the alga Sargassum densifolium and on organic matter associated with sediment. Free juveniles and symbiotic juveniles of O. venosa have intermediate δ13C values between both adult species. The high proportion of 13C in the symbiotic juveniles compared to the one in their conspecific adults indicates that their diet slightly differs from the latter and is closer to that of Ophiocoma scolopendrina. This raises the hypothesis that symbiotic juveniles steal neuston from their associated host, O. scolopendrina.


2001 ◽  
Vol 75 (3) ◽  
pp. 513-526 ◽  
Author(s):  
Kenneth G. Johnson

Caribbean coral reef communities were restructured by episodes of accelerated biotic change during the late Oligocene/early Miocene and the late Pliocene/early Pleistocene. However, rigorous description of the effects of rapid biotic change is problematic because preservation and exposure of coral-bearing deposits is not consistent in all stratigraphic intervals. In the Caribbean, early and middle Miocene exposures are more rare than late Miocene and Pliocene exposures. One exception is the late early to early middle Miocene Tamana Formation of Trinidad, and old and new collections from this unit were studied to determine the timing of recovery after the Oligocene/Miocene transition. A total of 41 species of zooxanthellate corals were recovered from the unit, including 21 new records. Within these assemblages, species first occurrences outnumber species last occurrences by a factor of four (31 first occurrences and eight last occurrences). The extension of the stratigraphic ranges of species previously first recorded in Pliocene sediments has reduced an apparent Pliocene pulse of origination, indicating that the Pliocene/Pleistocene transition was largely a result of accelerated extinction against a background of near-constant origination. The fact that few species last occur in the Tamana fauna indicates that the Oligocene/Miocene transition was complete by the end of the early Miocene.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lubos Polerecky ◽  
Takako Masuda ◽  
Meri Eichner ◽  
Sophie Rabouille ◽  
Marie Vancová ◽  
...  

Unicellular nitrogen fixing cyanobacteria (UCYN) are abundant members of phytoplankton communities in a wide range of marine environments, including those with rapidly changing nitrogen (N) concentrations. We hypothesized that differences in N availability (N2 vs. combined N) would cause UCYN to shift strategies of intracellular N and C allocation. We used transmission electron microscopy and nanoscale secondary ion mass spectrometry imaging to track assimilation and intracellular allocation of 13C-labeled CO2 and 15N-labeled N2 or NO3 at different periods across a diel cycle in Cyanothece sp. ATCC 51142. We present new ideas on interpreting these imaging data, including the influences of pre-incubation cellular C and N contents and turnover rates of inclusion bodies. Within cultures growing diazotrophically, distinct subpopulations were detected that fixed N2 at night or in the morning. Additional significant within-population heterogeneity was likely caused by differences in the relative amounts of N assimilated into cyanophycin from sources external and internal to the cells. Whether growing on N2 or NO3, cells prioritized cyanophycin synthesis when N assimilation rates were highest. N assimilation in cells growing on NO3 switched from cyanophycin synthesis to protein synthesis, suggesting that once a cyanophycin quota is met, it is bypassed in favor of protein synthesis. Growth on NO3 also revealed that at night, there is a very low level of CO2 assimilation into polysaccharides simultaneous with their catabolism for protein synthesis. This study revealed multiple, detailed mechanisms underlying C and N management in Cyanothece that facilitate its success in dynamic aquatic environments.


The Sea ◽  
2016 ◽  
Vol 21 (1) ◽  
pp. 36-43
Author(s):  
JEONG BAE KIM ◽  
WON-CHAN LEE ◽  
HYUNG CHUL KIM ◽  
SOKJIN HONG ◽  
KYEONG DONG PARK

Coral Reefs ◽  
2017 ◽  
Vol 37 (1) ◽  
pp. 145-152 ◽  
Author(s):  
Ross Cunning ◽  
Rachel N. Silverstein ◽  
Andrew C. Baker

1992 ◽  
Vol 6 ◽  
pp. 43-43
Author(s):  
Ann F. Budd ◽  
Thomas A. Stemann ◽  
Kenneth G. Johnson

Study of the stratigraphic ranges of reef coral species in scattered sequences (Dominican Republic, Bahamas, Costa Rica, Jamaica, and Florida) suggests that a major episode of faunal turnover occurred in the Caribbean region between early Pliocene and mid Pleistocene time. In a data set composed of all reef corals except the families Mussidae and Oculinidae and the genera Cladocora and Madracis, approximately 90% of the Mio-Pliocene fauna, composed of as many as 65–70 species, became extinct during this time interval. Ten of 27 genera became extinct. Despite the high numbers of extinctions, the total number of species in the Caribbean reef coral fauna dropped only slightly over the time interval, due to similar numbers of originations and extinctions in the fauna. With one possible exception, new species arose in surviving genera, and no new genera formed.Although similar numbers of species became extinct within early Pliocene, late Pliocene, and early Pleistocene time units, shallow water communities experienced higher numbers of extinctions during the late Miocene and early Pliocene. Deeper water communities experienced higher numbers of extinctions during the late Pliocene and early Pleistocene. Species surviving the turnover episode occur in deeper water communities and belong predominantly to the family Agariciidae. Nearshore grass flat communities contain the highest number of early extinctions. No difference in extinction patterns could be detected between taxa which reproduce primarily by fragmentation and those that reproduce primarily by larval recruitment. Although originations appear evenly distributed among community types, a large number occur in Florida along the northern margin of faunal distribution.The increased extinctions in shallow water communities and increased originations in the north suggest that turnover occurred primarily in response to change in abiotic factors such as temperature and siltation, and not in response to species-area effects associated with sea level change.


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