Bifurcaria galapagensis
| Bifurcaria galapagensis | |
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Scientific classification 
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| Domain: | Eukaryota |
| Clade: | Diaphoretickes |
| Clade: | SAR |
| Clade: | Stramenopiles |
| Phylum: | Gyrista |
| Subphylum: | Ochrophytina |
| Class: | Phaeophyceae |
| Order: | Fucales |
| Family: | Sargassaceae |
| Genus: | Bifurcaria |
| Species: | B. galapagensis
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| Binomial name | |
| Bifurcaria galapagensis | |
| Synonyms | |
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Bifurcaria galapagensis, the Galapagos stringweed, is a species of brown algae seaweed endemic to the Galapagos Islands. The IUCN Red List categorized the algae as Critically Endangered (Possibly Extinct), after a March 2007 assessment noted that the plant hadn't been since 1983.[1]
William Randolph Taylor documented Galapagos stringweed (then Blossevillea galapagensis) alongside myriad other Pacific marine algae during a three-month expedition to Baja California, Central and South America, and the Galapagos Islands.[2] In the intertidal zones of Isla Santa Maria, Taylor notes that "[t]he dominant algal species appeared to be Blossevillea galapagensis, a notable fucoid endemic known from the time of the Vettor Pisani Expedition. This grew high on the littoral rocks in great abundance." Taylor notes seven separate expeditions from 1872 to 1934 (including his own) that found this species.
Before its disappearance, there was some evidence to suggest that Galapagos stringweed had both antimicrobial and antimitotic properties.[3][4]
Description
[edit]Taylor described Bifurcaria galapagensis:
Plants gregarious, olivaceous, firm in texture, black and brittle when dried, exceeding 4 dm in height, the basal holdfasts small, irregularly lobed ; branching close to the base into several main axes which are about 1.0-1.5 mm diam., and which branch irregularly into smaller divisions, especially above bearing scattered lateral determinate aculeate to filiform branchlets 1-3 cm long ; above irregularly dichotomously branched, the sterile divisions slender, near the top somewhat fastigiate ; fertile branches dichotomously or sometimes laterally branched, the divisions nodulose, to 2.5 mm diam., tapering, the conceptacles hermaphrodite, the oval sporangia 133-200 μ long, 46-80 μ diam., each producing one egg.[2]
Taxonomy
[edit]The classification of Bifurcaria galapagensis is uncertain, likely in part due to its scarcity; noted AlgaeBase founder M.D. Guiry points out that as of December 2017, members of the genus Bifurcaria are found only in the eastern Atlantic.[5] This species was first classified as Fucodium galapagense in 1886 as it was apparently similar to F. tuberculatum.[6] Bifurcaria galapagensis has several homotypic synonyms as its genus has been reassessed:[5]
- Pelvetia galapagensis (Piccone & Grunow) De Toni 1895
- Blossevillea galapagensis (Piccone & Grunow) W.R. Taylor 1945: Based on similarities between "fructiferous parts and ha[ving] but one egg in each sporangium,"[2] Taylor decided that Galapagos stringweed was more closely related to Blossevillea brandegeei Setch & Gardner 1913 than to Bifurcaria or Pelvetia.
Likely extinction
[edit]Researchers applying a key biodiversity area (KBA) methodology to the Galapagos Marine Reserve conducted numerous field surveys between 2000 and 2006 were unable to find a single B. galapagensis specimen.[7] The researchers considered "crypsis or insufficient search effort" as possible reasons for their inability to locate sought-after species but determined that "a lack of sighting ... reflect[ed] true absence[.]" Bifurcaria galapagensis was later described--by many of the same researchers--as "regarded as probably extinct".[8] The Spring/Summer 2010 issue of Galapagos News lamented that "[o]ne in five of the marine species listed as threatened in Galapagos may already be extinct" and that "[i]t may be too late to save the endemic Galapagos stringweed[.]"[9]
References
[edit]- ^ a b Miller, K.A.; Garske, L. & Edgar, G. (2007). "Bifurcaria galapagensis". IUCN Red List of Threatened Species. 2007: e.T63593A12686056. doi:10.2305/IUCN.UK.2007.RLTS.T63593A12686056.en. Retrieved 16 May 2024.
- ^ a b c "Allan Hancock Pacific expeditions [reports]". Allan Hancock Foundation Publications. 12. Los Angeles, California: The University of Southern California Press: 27, 112, 362–3. 1945 – via Biodiversity Heritage Library.
- ^ Sun, Hao H.; Ferrara, Nancy M.; McConnell, Oliver J.; Fenical, William (1980-01-01). "Bifurcarenone, an inhibitor of mitotic cell division from the brown alga bifurcaria galapagensis". Tetrahedron Letters. 21 (33): 3123–3126. doi:10.1016/S0040-4039(00)77425-9. ISSN 0040-4039.
- ^ Mori, Kenji; Uno, Tetsuyuki (1989-01-01). "Synthesis and structure revision of bifurcarenone, a unique monocyclic diterpene in combination with a hydroquinone C7 unit as an inhibitor of mitotic cell division". Tetrahedron. 45 (7): 1945–1958. doi:10.1016/S0040-4020(01)80058-2. ISSN 0040-4020.
- ^ a b Guiry, M.D.; Guiry, G.M. (10 January 2020). "Bifurcaria galapagensis (Piccone & Grunow) Womersley 1964". AlgaeBase. World-wide electronic publication. Galway: National University of Ireland. Retrieved May 15, 2024.
- ^ "Revue Bibliographique". Bulletin de la Société Botanique de France [Bibliographical Review in the Bulletin of the Botanical Society of France v.34] (in French). Vol. v.34. Paris: Imprimeries réunies. 1887. pp. 162–3.
- ^ Edgar, Graham J.; Banks, Stuart; Bensted‐Smith, Robert; Calvopiña, Monica; Chiriboga, Angel; Garske, Lauren E.; Henderson, Scott; Miller, Kathy Ann; Salazar, Sandie (September 2008). "Conservation of threatened species in the Galapagos Marine Reserve through identification and protection of marine key biodiversity areas". Aquatic Conservation: Marine and Freshwater Ecosystems. 18 (6): 955–968. doi:10.1002/aqc.901. ISSN 1052-7613.
- ^ Edgar, Graham J.; Banks, Stuart A.; Brandt, Margarita; Bustamante, Rodrigo H.; Chiriboga, Angel; Earle, Sylvia A.; Garske, Lauren E.; Glynn, Peter W.; Grove, Jack S.; Henderson, Scott; Hickman, Cleve P.; Miller, Kathy A.; Rivera, Fernando; Wellington, Gerald M. (October 2010). "El Niño, grazers and fisheries interact to greatly elevate extinction risk for Galapagos marine species". Global Change Biology. 16 (10): 2876–2890. doi:10.1111/j.1365-2486.2009.02117.x. ISSN 1354-1013.
- ^ Nicholls, Henry, ed. (Spring–Summer 2010). "News from Galapagos" (PDF). Galapagos News. Galapagos Conservancy. Marine Alarm. ISSN 1468-8514. Retrieved May 15, 2024.
One in five of the marine species listed as threatened in Galapagos may already be extinct, warn researchers. The International Union for the Conservation of Nature (IUCN) currently recognizes 43 marine species at risk of extinction in Galapagos. It may be too late to save the endemic Galapagos stringweed and several species of algae on this Red List, report scientists in Global Change Biology. Several factors are likely to have played a part in the declining abundance of these species.
Further reading
[edit]- The Galapagos: Proceedings of the Symposia of the Galapagos International Scientific Project (1966) edited by Robert I. Bowman, University of California Press, Berkeley and Los Angeles. See chapter 19, "Status of our Knowledge of the Galapagos Benthic Marine Algal Flora Prior to the Galapagos International Scientific Project" by Paul C. Silva. Includes a table of Galapagos expeditions from Darwin until the date of publication, a list of scientific literature cited, a chart detailing all 311 then-known regional algae.
- Holocene Extinctions (2009) edited by Samuel T. Turvey, Oxford University Press. See chapter 6, "Holocene extinctions in the sea" by Nicholas K. Dulvy, John K. Pinnegar, and John D. Reynolds, especially chapter 6.8, "A brief overview of known marine extinctions."