Linking local to global properties in branching modular networks: gorgonian coral colonies

Cadena, Nini Johanna; Rey, Camilo; Hernández-Hoyos, Marcela; Sánchez, Jesús D.; Teillaud, Stanislas; Ardila, Néstor E.; Sánchez, Juan A.

doi:10.1007/s00227-009-1380-1

Cited by 8 publications

(8 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Despite the small sample size, the analysis of the data shows that proteins and car bohydrates in unaffected colonies are distributed uniformly through first-, second-and third-order bran ches, as shown by Rossi et al (2006a). As hydrodynamics dictate that apical polyps are more efficient in capturing prey (Dai & Lin 1993), this confirms an efficient transport of food from apical branches to the more central parts of the colony (sensu Murdock 1978a, b), which reinforces the stem to keep up with peripheral growth (Cadena et al 2010). In contrast, tertiary branches in colonies affected by epibionts contained significantly lower protein levels.…”

Section: Fecundity and Balance Of Energy Reservesmentioning

confidence: 74%

Anthropogenic effects on reproductive effort and allocation of energy reserves in the Mediterranean octocoral Paramuricea clavata

Tsounis¹,

Martínez²,

Bramanti³

et al. 2012

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

In order to better understand the sources, patterns and consequences of anthro pogenic effects on populations of the Mediterranean gorgonian Paramuricea clavata, we examined the proportion of injured colonies among populations exposed to a combination of anthropogenic disturbances (recreational cast fishing, commercial lobster pots, gill nets and SCUBA diving), as well as the physiological response of injured corals. Between 10 and 33% of the colonies in unprotected populations were partially colonized by epibionts, most likely following tissue injury, whereas only 4 to 10% of the populations in a marine protected area were affected. Populations that were simultaneously exposed to fishing as well as intensive SCUBA diving showed the highest proportion of colonization. Colonies with approximately 30 to 35% of epibiont coverage showed significantly lower numbers of gonads per polyp. Similarly, concentrations of lipids were lower in females with epibionts, thus indicating allocation of resources into recovery of injured tissue instead of reproduction. Furthermore, whereas unaffected colonies showed a uniform distribution of carbohydrates and proteins through apical branches to more central ones, colonies with epibionts had significantly lower protein concentrations in branches that are positioned 3 branching order levels closer to the stem. The results thus indicate a preference of apical growth in recovering colonies, via a different distribution of food within the colony. Reproductive success in surface-brooding corals growing on walls and overhangs might also be reduced by SCUBA bubbles from divers passing below, as bubbles efficiently remove eggs brooded on colony branches.

show abstract

Section: Fecundity and Balance Of Energy Reservesmentioning

confidence: 74%

Anthropogenic effects on reproductive effort and allocation of energy reserves in the Mediterranean octocoral Paramuricea clavata

Tsounis¹,

Martínez²,

Bramanti³

et al. 2012

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…Responses to variations in water quality, thus heterotrophic feeding capacity, are incurred through polyp density as opposed to size, yet both canal number and dimensions remained unchanged in both morphotypes. The exact function of stem canals is unclear ( Cadena et al, 2010 ), although suggested to circulate and exchange water and nutrients throughout the coral colony ( Ellis & Solander, 1786 ). Canalisation/fixation at this level further suggests that photosynthetic gain with nutrient translocation at the cellular level between endosymbionts and host, are likely the primary trophic resource.…”

Section: Discussionmentioning

confidence: 99%

Environmental influences on the Indo–Pacific octocoralIsis hippurisLinnaeus 1758 (Alcyonacea: Isididae): genetic fixation or phenotypic plasticity?

Rowley

Pochon

Watling

2015

PeerJ

View full text Add to dashboard Cite

As conspicuous modular components of benthic marine habitats, gorgonian (sea fan) octocorals have perplexed taxonomists for centuries through their shear diversity, particularly throughout the Indo–Pacific. Phenotypic incongruence within and between seemingly unitary lineages across contrasting environments can provide the raw material to investigate processes of disruptive selection. Two distinct phenotypes of the Isidid Isis hippuris Linnaeus, 1758 partition between differing reef environments: long-branched bushy colonies on degraded reefs, and short-branched multi/planar colonies on healthy reefs within the Wakatobi Marine National Park (WMNP), Indonesia. Multivariate analyses reveal phenotypic traits between morphotypes were likely integrated primarily at the colony level with increased polyp density and consistently smaller sclerite dimensions at the degraded site. Sediment load and turbidity, hence light availability, primarily influenced phenotypic differences between the two sites. This distinct morphological dissimilarity between the two sites is a reliable indicator of reef health; selection primarily acting on colony morphology, porosity through branching structure, as well as sclerite diversity and size. ITS2 sequence and predicted RNA secondary structure further revealed intraspecific variation between I. hippuris morphotypes relative to such environments (ΦST = 0.7683, P < 0.001). This evidence suggests—but does not confirm—that I. hippuris morphotypes within the WMNP are two separate species; however, to what extent and taxonomic assignment requires further investigation across its full geographic distribution. Incongruence between colonies present in the WMNP with tenuously described Isis alternatives (Isis reticulata Nutting, 1910, Isis minorbrachyblasta Zou, Huang & Wang, 1991), questions the validity of such assignments. Furthermore, phylogenetic analyses confirm early taxonomic suggestion that the characteristic jointed axis of the Isididae is in fact a convergent trait. Thus the polyphyletic nature of the Isididae lies in its type species I. hippuris, being unrelated to the rest of its family members.

show abstract

“…Here we observed that stem canals fused at the branch tips, forming a unique chamber of complex architecture. In the analyzed apical regions of Muricea muricata the number of canals just before fusion varied from 10 to 12, whereas in another gorgonian species, Eunicea mammosa , the minimum number of canals found in a number of dissected colonies was sixteen, a multiple of eight [7]. Based on that previous observation, it was expected that the number of canals at the tips is connected and related to the number of polyp mesenteries, which is always eight in octocorals [8].…”

Section: Discussionmentioning

confidence: 99%

“…All we know at the moment is that it is a complex network spreading throughout the whole colony, that the number of canals decreases towards the branch tips and that the canal wall is densely packed with calcite spindle-like sclerites [7].…”

Section: Introductionmentioning

confidence: 99%

“…Noted for the first time by Leonardo Da Vinci, the number of vessels in a tree trunk is directly related to the number of leaves in the tree crown what is formally known today as the pipe-model theory [6] . Similarly, octocorals have a pseudo-vasculature composed of stem canals, and the number of canals at the main stem is related to the total number of branches in the colony [7] .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Semi-Automatic Method to Extract Canal Pathways in 3D Micro-CT Images of Octocorals

et al. 2014

Self Cite

View full text Add to dashboard Cite

The long-term goal of our study is to understand the internal organization of the octocoral stem canals, as well as their physiological and functional role in the growth of the colonies, and finally to assess the influence of climatic changes on this species. Here we focus on imaging tools, namely acquisition and processing of three-dimensional high-resolution images, with emphasis on automated extraction of canal pathways. Our aim was to evaluate the feasibility of the whole process, to point out and solve – if possible – technical problems related to the specimen conditioning, to determine the best acquisition parameters and to develop necessary image-processing algorithms. The pathways extracted are expected to facilitate the structural analysis of the colonies, namely to help observing the distribution, formation and number of canals along the colony. Five volumetric images of Muricea muricata specimens were successfully acquired by X-ray computed tomography with spatial resolution ranging from 4.5 to 25 micrometers. The success mainly depended on specimen immobilization. More than of the canals were successfully detected and tracked by the image-processing method developed. Thus obtained three-dimensional representation of the canal network was generated for the first time without the need of histological or other destructive methods. Several canal patterns were observed. Although most of them were simple, i.e. only followed the main branch or “turned” into a secondary branch, many others bifurcated or fused. A majority of bifurcations were observed at branching points. However, some canals appeared and/or ended anywhere along a branch. At the tip of a branch, all canals fused into a unique chamber. Three-dimensional high-resolution tomographic imaging gives a non-destructive insight to the coral ultrastructure and helps understanding the organization of the canal network. Advanced image-processing techniques greatly reduce human observer's effort and provide methods to both visualize and quantify the structures of interest.

show abstract

Linking local to global properties in branching modular networks: gorgonian coral colonies

Cited by 8 publications

References 25 publications

Anthropogenic effects on reproductive effort and allocation of energy reserves in the Mediterranean octocoral Paramuricea clavata

Anthropogenic effects on reproductive effort and allocation of energy reserves in the Mediterranean octocoral Paramuricea clavata

Environmental influences on the Indo–Pacific octocoralIsis hippurisLinnaeus 1758 (Alcyonacea: Isididae): genetic fixation or phenotypic plasticity?

A Semi-Automatic Method to Extract Canal Pathways in 3D Micro-CT Images of Octocorals

Contact Info

Product

Resources

About