Cymodocea nodosa
{{Short description|Species of plant in the family Cymodoceaceae}}
{{Speciesbox
|image = Cymodocea nodosa.jpg
|image_caption = Blossoming Cymodocea nodosa off the coast of Corsica
|status = LC
|status_system = IUCN3.1
|genus = Cymodocea
|species = nodosa
|authority = (Ucria) Asch. (1870)[http://www.eol.org/pages/1087289 Cymodocea nodosa (Ucria) Asch]. Encyclopedia of Life. Retrieved 2011-08-17
|synonyms = Cymodocea aequorea K.D.Koenig
Cymodocea major (Willd.) Grande
Cymodocea preauxiana Webb & Berthel.
Cymodocea webbiana A.Juss.
Phucagrostis major Theophr. ex Cavolini
Phucagrostis nodosa (Ucria) Kuntze
Kernera nodosa (Ucria) Schult. & Schult.f.
Zostera mediterranea DC.
Zostera nodosa Ucria
}}
Cymodocea nodosa is a species of seagrass in the family Cymodoceaceae and is sometimes known as little Neptune grass.[http://wildlife-archipelago.gr/wordpress/marine-flora/lesser-neptune-grass-cymodocea-nodosa/ Lesser Neptune Grass (Cymodocea nodosa)] {{webarchive|url=https://web.archive.org/web/20120330231922/http://wildlife-archipelago.gr/wordpress/marine-flora/lesser-neptune-grass-cymodocea-nodosa/ |date=2012-03-30 }} Archipelagos Wildlife Library. Retrieved 2011-08-17 As a seagrass, it is restricted to growing underwater and is found in shallow parts of the Mediterranean Sea and certain adjoining areas of the Atlantic Ocean.
Description
C. nodosa has light green or greyish-green leaves. They are very narrow but may be up to forty centimetres long. Each leaf has seven to nine veins running along its length. The plant produces rhizomes which are only 1 mm in diameter and have leaf scars at intervals.Boudouresque, C.-F..A.M.a.M.V., 1992. Guide des Algues des Mers d’Europe. Paris: Delachaux et Niestle. Inconspicuous grass-like flowers are sometimes produced at the end of long stems in the spring when water temperatures begin to rise after their winter minimum. The pollen is liberated into the sea and the seeds remain dormant until the following spring.{{cite journal | title = Reproductive phenology of the Mediterranean seagrasses Posidonia oceanica (L.) Delile, Cymodocea nodosa (Ucria) Aschers., and Zostera noltii Hornem | doi=10.1016/0304-3770(91)90080-O | volume=40 | issue = 4 | year=1991 | journal=Aquatic Botany | pages=343–362 | author=Buia M.C., Mazzella L.| bibcode=1991AqBot..40..343B }}
Distribution and habitat
This seagrass is found in shallow parts of the Mediterranean Sea and the adjoining parts of the Atlantic Ocean, the coasts of Portugal, Mauritania and Senegal and round the Canary Islands and Madeira. It grows at depths of down to nineteen{{cite web | url=https://alivefund.org/arxius/1552 | title=Crònica immersió 17 de setembre del 2020 | access-date=2020-09-27 | archive-date=2020-10-20 | archive-url=https://web.archive.org/web/20201020192542/https://alivefund.org/arxius/1552 | url-status=dead }} metres in sandy sediments in sheltered locations and needs clear waters for photosynthesis. Off the Catalan coast in the western Mediterranean, a single meadow of this grass covering at least {{convert|800|hectare}} has been discovered.{{ cite web | url = https://www.viladeroses.cat/la-badia-de-roses-detecta-una-extensio-de-800-ha-coberta-per-una-praderia-de-cymodocea-nodosa/ | title = La badia de Roses detecta una extensió de 800 ha coberta per una praderia de Cymodocea nodosa|publisher=Vila de Roses |accessdate=27 September 2020}}
Ecology
Cymodocea nodosa grows in meadows on the seabed[http://www.iucnredlist.org/apps/redlist/details/153535/0/full Cymodocea nodosa] IUCN Red List of Threatened Species. Retrieved 2011-08-17 and is sometimes associated with the other seagrasses, Zostera noltii and Posidonia oceanica and the seaweeds Caulerpa prolifera and Caulerpa racemosa. Although it is adversely affected by mechanical disturbance such as trawling and by pollution, and although it is in competition with other seagrass species, C. nodosa is not considered to be threatened.
In the Canary Islands, fifty-three species of epiphytic algae were found to grow on the leaves and rhizomes of C. nodosa. Many of these were encrusting species of Corallinaceae.[http://www.reference-global.com/doi/abs/10.1515/botm.1998.41.1-6.543 Distribution of the epiphytes along the leaves of Cymodocea nodosa in the Canary Islands]{{Dead link|date=July 2019 |bot=InternetArchiveBot |fix-attempted=yes }} Retrieved 2011-08-17
Seagrass meadows have high biological productivity and are rich, biodiverse habitats. Fish species associated with C. nodosa in a coastal lagoon in south east Spain include Atherina boyeri, Pomatoschistus marmoratus, Liza aurata, Liza saliens, Syngnathus abaster and Aphanius iberus. The meadows are an important rearing ground for juvenile fish.[http://www.limnetica.net/Limnetica/limne26b/L26b341_Fish_assemblages_Cymodocea_Caulerpa_meadows.pdf Fish assemblages associated with Cymodocea nodosa and Caulerpa prolifera meadows in the shallow areas of the Mar Menor coastal lagoon] {{webarchive|url=https://web.archive.org/web/20120317152450/http://www.limnetica.net/Limnetica/limne26b/L26b341_Fish_assemblages_Cymodocea_Caulerpa_meadows.pdf |date=2012-03-17 }} Retrieved 2011-08-17 Invertebrates associated with seagrass meadows include polychaete worms,[http://www.mendeley.com/research/polychaetes-associated-to-a-cymodocea-nodosa-meadow-in-the-canary-islands-assemblage-structure-temporal-variability-and-vertical-distribution-compared-to-other-mediterranean-seagrass-meadows Polychaetes associated with Cymodocea nodosa meadow in the Canary Islands: assemblage structure, temporal variability and vertical distribution compared to other Mediterranean seagrass meadows] {{Webarchive|url=https://web.archive.org/web/20120406114419/http://www.mendeley.com/research/polychaetes-associated-to-a-cymodocea-nodosa-meadow-in-the-canary-islands-assemblage-structure-temporal-variability-and-vertical-distribution-compared-to-other-mediterranean-seagrass-meadows/ |date=2012-04-06 }} Retrieved 2011-08-17 amphipods, isopods, decapods and molluscs.[https://books.google.com/books?id=emkDvfazY2UC&dq=Cymodocea+nodosa+associated+isopod&pg=PA399 Biology of Posidonia] Seagrasses: Biology, Ecology and Conservation. Retrieved 2011-08-17
C. nodosa tends to grow in patches. This is because it favours unstable sandy sediments and subaqueous dunes tend to move over time. If the sand accretion is not too fast, the stolons can grow vertically through it, but the seagrass can be overwhelmed by rapid accretion. Patch death was mostly caused by erosion as roots were uncovered, encrusting and drilling organisms increased and plants were swept away. The dune movement cycle tended to take two to six years, which gives the seagrass time to recolonise bare areas. Sand accretion also stimulates flowering and dormant seeds can enable recolonisation when conditions allow it.{{cite journal |jstor=2261592 |title=Coupling of seagrass (Cymodocea nodosa) dynamics with subaqueous dune migration |author1=Nuria Marba |author2=Carlos M. Duarte |journal=Journal of Ecology |volume=83 |issue=3 |date=Jun 1995 |pages=381–389 |doi=10.2307/2261592}}
The fact that the pattern of C. nodosa growth changes as sand is deposited provides a means of measuring the travel of subaqueous dunes. In the Alfacs Bay in the northwest Mediterranean Sea, it was found that the rate of dune advance averaged 13 metres per year, and that the seagrasses could be used to monitor movement rates ranging from 0.15 metres to 980 metres per year.{{cite journal |jstor=2838368 |title=Migration of large-scale subaqueous bedforms measured with seagrasses (Cymodocea nodosa) as tracers |author1=Nuria Marba |author2=Just Cebrian |author3=Susana Enriquez |author4=Carlos M. Duarte |journal=Limnology and Oceanography |volume=39 |issue=1 |date=Jan 1994 |pages=126–133 |doi=10.4319/lo.1994.39.1.0126|bibcode=1994LimOc..39..126M }}
The invasive alga Caulerpa taxifolia is often associated with C. nodosa. It has an extensive rhizoidal system that anchors it to a sandy substrate. The alga is better able to extract nutrients from the substrate than can the seagrass. A study was undertaken near the island of Elba, Italy, in which slow release fertiliser sticks were added to test plots of the seabed where the seagrass and alga both grew. It was found that although both species responded with increased growth rates, the seagrass was relatively disadvantaged in that increased growth of the alga restricted the amount of sunlight reaching the seagrass whereas the alga was less constrained by limited light.[http://plosjournal.deepdyve.com/lp/de-gruyter/a-pilot-study-of-nutrient-enriched-sediments-in-a-cymodocea-nodosa-bed-Tkrq0eDgi0 A Pilot Study of Nutrient Enriched Sediments in a Cymodocea nodosa Bed Invaded by the Introduced Alga Caulerpa taxifolia] Retrieved 2011-08-17
References
{{Reflist|colwidth=33em}}
External links
- Fotos of Cymodocea nodosa in [https://www.inaturalist.org/observations?locale=en-UK&place_id=97391&preferred_place_id=6774&subview=grid&taxon_id=131135 iNaturalist]
{{Taxonbar|from=Q2294077}}
Category:Biota of the Atlantic Ocean
Category:Biota of the Mediterranean Sea
Category:Biota of the Adriatic Sea
Category:Biota of the Canary Islands
Category:Taxa named by Bernardino da Ucria