Gelidium

Gelidium is a genus of thalloid red algae comprising 124 species. Its members are known by a number of common names.[note 1] Specimens can reach around 2–40 cm (0.79–16 in) in size. Branching is irregular, or occurs in rows on either side of the main stem. Gelidium produces tetraspores. Many of the algae in this genus are used to make agar. Chaetangium is a synonym.[1]

Gelidium
Gelidium amansii
Scientific classification
(unranked):	Archaeplastida
Division:	Rhodophyta
Class:	Florideophyceae
Order:	Gelidiales
Family:	Gelidiaceae
Genus:	Gelidium J.V. Lamouroux, 1813

Gelidium as environmental records

Gelidium species have been collected, pressed and maintained in herbaria and personal collections from the 1850s onwards since seaweed collecting became a popular pastime for the middle classes as well as scientists in Europe and North America.[2] These numerous well-documented specimens can provide information beyond taxonomy.[3]

Sensitive measurement of stable nitrogen isotope ratios in Gelidium species collected in southern Monterey Bay between 1878 and 2018 showed a pattern of changes that matched with changes in the California current and provided support for a theory about the end of the local fishing industry.[4] Nitrogen isotope ratios are well established as a measure of nutrient productivity in aquatic ecosystems. The California current runs along coastal California and correlation with information on fish catches indicates that an increase in nutrient-rich cold water is important for fish productivity, notably sardines.[5] The California current has only been measured since 1946. The correlations with the Gelidium nitrogen ratios allowed the California current to be projected back into the nineteenth century and compared with historical records of fish catches.[4] The data matched, notably for the highest sardine catches through the 1930s and then the sudden decrease from 1945 to 1950 that ended the Monterey cannery industry. This information supports the theory that environmental changes as well as overfishing caused the collapse of the local fishery business. More broadly, this suggests that elemental analysis of historical samples of macroalgae can provide evidence of primary productivity processes. The species used included specimens of G. coulteri, G. robustum, G. purpurascens, G. pusillum and G. arborescens collected over a 140-year timespan from the 6 km coastline between Point Pinos, Pacific Grove and Cannery Row, Monterey in California, US.[4]

Species

Gelidium affine Gelidium allanii Gelidium amamiense Gelidium amansii Gelidium ambiguum Gelidium americanum Gelidium anthonini Gelidium applanatum Gelidium arborescens Gelidium arenarium Gelidium asperum Gelidium australe Gelidium bernabei Gelidium bipectinatum Gelidium canariense Gelidium cantabricum Gelidium capense Gelidium caulacantheum Gelidium ceramoides Gelidium chilense Gelidium coarctatum Gelidium concinnum Gelidium congestum Gelidium coronadense Gelidium coulteri Gelidium crinale Gelidium crispum Gelidium deciduum Gelidium decompositum Gelidium delicatulum Gelidium divaricatum Gelidium elegans Gelidium elminense Gelidium fasciculatum

Gelidium filicinum Gelidium flaccidum Gelidium floridanum Gelidium foliaceum Gelidium foliosum Gelidium galapagense Gelidium hancockii Gelidium heterocladum Gelidium hommersandii Gelidium howei Gelidium hypnosum Gelidium inagakii Gelidium inflexum Gelidium intertextum Gelidium isabelae Gelidium japonicum Gelidium johnstonii Gelidium kintaroi Gelidium latiusculum Gelidium lingulatum Gelidium linoides Gelidium longipes Gelidium macnabbianum Gelidium madagascariense Gelidium maggsiae Gelidium masudae Gelidium microdentatum Gelidium microdon Gelidium microdonticum Gelidium microphyllum Gelidium microphysa Gelidium micropterum Gelidium minusculum Gelidium multifidum

Gelidium musciforme Gelidium nova-granatense Gelidium nudifrons Gelidium omanense Gelidium pacificum Gelidium planiusculum Gelidium pluma Gelidium pristoides Gelidium profundum Gelidium pseudointricatum Gelidium pteridifolium Gelidium pulchellum Gelidium pulchrum Gelidium pulvinatum Gelidium purpurascens Gelidium pusillum Gelidium reediae Gelidium refugiensis Gelidium regulare Gelidium reptans Gelidium rex Gelidium rigens Gelidium robustum Gelidium samoense Gelidium sclerophyllum Gelidium secundatum Gelidium semipinnatum Gelidium serrulatum Gelidium sesquipedale Gelidium sinicola Gelidium spathulatum Gelidium spinosum Gelidium subfastigiatum Gelidium tenue

Gelidium tsengii Gelidium umbricola Gelidium usmanghanii Gelidium vagum Gelidium venetum Gelidium venturianum Gelidium versicolor Gelidium vietnamense Gelidium vittatum Gelidium yamadae Gelidium zollingeri

Notes

1. Recorded common names are tengusa, makusa, genso, niu mau tsai, japansche scheleiachtige mos, steen-or klipbloem, hay tsay, olus marinus, sajur laut, tschintschau, tschoo-hoae, onikusa, hirakusa, obusa, rødalge-slaegt, gelídeos, punalevä-suku, tokoroten, kanten, tokoro-tengusa, kinukusa, isingglass, hai-ten-gusa, tocoroten, tengusa-agar, limu lo-loa, hai-tengusa, onigusa, oyakusa, kanten weed, goumaocai, hime tengusa, shihua and tanmae.

References

• Guiry, M.D.; Guiry, G.M. (2008). "Gelidium". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Retrieved 2009-04-18.

1. Tronchin, E. M.; Freshwater, D. W.; Bolton, J. J.; Anderson, R. J. (2002). "A Reassessment and Reclassification of Species in the Genera Onikusa Akatsuka and Suhria J. Agardh ex Endlicher (Gelidiales, Rhodophyta) Based on Molecular and Morphological Data". Botanica Marina. 45 (6): 548–558. doi:10.1515/BOT.2002.058.
2. Giaimo, Cara. "The Forgotten Victorian Craze for Collecting Seaweed". Atlas Obscura. Retrieved 27 October 2020.
3. Trethewey, Laura. "What Victorian-era seaweed pressings reveal about our changing seas". The Guardian. Retrieved 27 October 2020.
4. Miller, Emily A; Lisin, Susan E; Smith, Celia M; Van Houtan, Kyle S (2020). "Herbaria macroalgae as a proxy for historical upwelling trends in Central California". Proceedings of the Royal Society B. 287: 20200732. doi:10.1098/rspb.2020.0732. Retrieved 27 October 2020.
5. Ware, D M; Thompson, R E (1991). "Link between longterm variability in upwelling and fish production in the northeast Pacific Ocean". Can. J. Fish. Aquat. Sci. 48: 2296–2306. doi:10.1139/f91-270. Retrieved 27 October 2020.

• Toefy, R., Gibbons, M.J. & McMillan, I.K. 2005. The foraminifera associated with the alga Gelidium pristoides, South Africa. African Invertebrates 46: 1-26.

External links

• Images of Gelidium at Algaebase