Ghent University Academic Bibliography

Advanced

Distinctive morphological features, life-cycle phases and seasonal variations in subtropical populations of Dictyota dichotoma (Dictyotales, Phaeophyceae)

Ana Tronholm, Marta Sanson, Julio Afonso-Carrillo and Olivier De Clerck UGent (2008) BOTANICA MARINA. 51(2). p.132-144
abstract
Although it has been suggested that the distribution of Dictyota dichotoma is probably restricted to the European Atlantic Ocean and the Mediterranean Sea, its occurrence in the Canary Islands (new southernmost distribution limit) is confirmed by nuclear ribosomal sequence data (LSU rDNA). Even though D. dichotoma has been described and illustrated prominently in early studies of brown algae, the species remains difficult to characterize due to considerable morphological plasticity. An exhaustive analysis of several quantitative characters confirms significant morphological variation both seasonally and between life-cycle phases. The species may be characterized in the Canary Islands only by the following qualitative features: erect thallus attached by a single holdfast, subdichotomous branches always of similar width, straight terminal segments and smooth margins and an entirely unilayered medulla. In the Canary Islands, D. dichotoma is an aseasonal annual with at least three overlapping generations in which sporophytes and gametophytes grow simultaneously. Thallus life span seems to be less than 3 months. The species occurs throughout the year, but as cryptic microthalli in autumn. Two abundance peaks were detected with the maximum value in February (6.2 thalli m(-2)). The optimum reproductive stage (88.3% fertile specimens) occurred in winter and the maximum vegetative stage (maximum thallus length: 18.6 cm) in summer. Sporophytes outnumbered gametophytes throughout the year, with ratios decreasing from 13.2 +/- 1.1 in winter to 1.9 +/- 0.2 in summer. Gametophytes made up to 25% of the population and fertile thalli were always dominant. The populations from the Canaries exhibited a temporal displacement compared to northern populations with the favorable period in the coldest season (winter) and the resting period in the warmest season (autumn).
Please use this url to cite or link to this publication:
author
organization
year
type
journalArticle (original)
publication status
published
keyword
morphology, nuclear ribosomal sequence data (LSU rDNA), Dictyota dichotoma, Canary Islands, COAST, ALGAE, ISLANDS, PATTERNS, AUSTRALIA, phenology, PHENOLOGY, PERIODICITY, NORTH-ATLANTIC, REPRODUCTION, seasonal variation
journal title
BOTANICA MARINA
Bot. Marina
volume
51
issue
2
pages
132 - 144
Web of Science type
Article
Web of Science id
000257672000006
JCR category
PLANT SCIENCES
JCR impact factor
0.844 (2008)
JCR rank
97/155 (2008)
JCR quartile
3 (2008)
ISSN
0006-8055
DOI
10.1515/BOT.2008.017
language
English
UGent publication?
yes
classification
A1
id
746115
handle
http://hdl.handle.net/1854/LU-746115
date created
2009-09-09 09:04:19
date last changed
2016-12-19 15:46:35
@article{746115,
  abstract     = {Although it has been suggested that the distribution of Dictyota dichotoma is probably restricted to the European Atlantic Ocean and the Mediterranean Sea, its occurrence in the Canary Islands (new southernmost distribution limit) is confirmed by nuclear ribosomal sequence data (LSU rDNA). Even though D. dichotoma has been described and illustrated prominently in early studies of brown algae, the species remains difficult to characterize due to considerable morphological plasticity. An exhaustive analysis of several quantitative characters confirms significant morphological variation both seasonally and between life-cycle phases. The species may be characterized in the Canary Islands only by the following qualitative features: erect thallus attached by a single holdfast, subdichotomous branches always of similar width, straight terminal segments and smooth margins and an entirely unilayered medulla. In the Canary Islands, D. dichotoma is an aseasonal annual with at least three overlapping generations in which sporophytes and gametophytes grow simultaneously. Thallus life span seems to be less than 3 months. The species occurs throughout the year, but as cryptic microthalli in autumn. Two abundance peaks were detected with the maximum value in February (6.2 thalli m(-2)). The optimum reproductive stage (88.3\% fertile specimens) occurred in winter and the maximum vegetative stage (maximum thallus length: 18.6 cm) in summer. Sporophytes outnumbered gametophytes throughout the year, with ratios decreasing from 13.2 +/- 1.1 in winter to 1.9 +/- 0.2 in summer. Gametophytes made up to 25\% of the population and fertile thalli were always dominant. The populations from the Canaries exhibited a temporal displacement compared to northern populations with the favorable period in the coldest season (winter) and the resting period in the warmest season (autumn).},
  author       = {Tronholm, Ana and Sanson, Marta and Afonso-Carrillo, Julio and De Clerck, Olivier},
  issn         = {0006-8055},
  journal      = {BOTANICA MARINA},
  keyword      = {morphology,nuclear ribosomal sequence data (LSU rDNA),Dictyota dichotoma,Canary Islands,COAST,ALGAE,ISLANDS,PATTERNS,AUSTRALIA,phenology,PHENOLOGY,PERIODICITY,NORTH-ATLANTIC,REPRODUCTION,seasonal variation},
  language     = {eng},
  number       = {2},
  pages        = {132--144},
  title        = {Distinctive morphological features, life-cycle phases and seasonal variations in subtropical populations of Dictyota dichotoma (Dictyotales, Phaeophyceae)},
  url          = {http://dx.doi.org/10.1515/BOT.2008.017},
  volume       = {51},
  year         = {2008},
}

Chicago
Tronholm, Ana, Marta Sanson, Julio Afonso-Carrillo, and Olivier De Clerck. 2008. “Distinctive Morphological Features, Life-cycle Phases and Seasonal Variations in Subtropical Populations of Dictyota Dichotoma (Dictyotales, Phaeophyceae).” Botanica Marina 51 (2): 132–144.
APA
Tronholm, A., Sanson, M., Afonso-Carrillo, J., & De Clerck, O. (2008). Distinctive morphological features, life-cycle phases and seasonal variations in subtropical populations of Dictyota dichotoma (Dictyotales, Phaeophyceae). BOTANICA MARINA, 51(2), 132–144.
Vancouver
1.
Tronholm A, Sanson M, Afonso-Carrillo J, De Clerck O. Distinctive morphological features, life-cycle phases and seasonal variations in subtropical populations of Dictyota dichotoma (Dictyotales, Phaeophyceae). BOTANICA MARINA. 2008;51(2):132–44.
MLA
Tronholm, Ana, Marta Sanson, Julio Afonso-Carrillo, et al. “Distinctive Morphological Features, Life-cycle Phases and Seasonal Variations in Subtropical Populations of Dictyota Dichotoma (Dictyotales, Phaeophyceae).” BOTANICA MARINA 51.2 (2008): 132–144. Print.