Ulva

Ulva

Languages: English

Overview

Brief Summary

Ulva is a genus of green algae known commonly as sea lettuce or green laver. Ulva seaweeds are found worldwide in nitrogen-rich marine habitats attached to rocks in the mid to low intertidal zone (Lee 2008; Kirby 2001). The fronds of Ulva usually grow as sheets, but some species exist in a hollow cylindrical form. These cylindrical species were previously classified as a distinct genus, Enteromorpha, but are now included in Ulva.  (Lee 2008; Hayden et al 2003). The blades can grow up to 40 cm long, but are very thin—only 2 cells thick (Lee 2008).

Ulva is eaten by humans in soups, salads, and sushi (Lee 2008 and references within; Kirby 2001).

Author(s): Campbell, Dana
Rights holder(s): Campbell, Dana

Description

Life Cycle

Ulva goes through an isomorphic alternation of generations.  Adult gametophytes produce only female or male gamets, which are positively phototactic, and move with flagella.  They are released in swarms coordinated by lunar cycles and tides.  When the zygote is formed it becomes negatively phototactic and swims to the bottom to settle, and germinates within a few days.  The haploid phase of the life cycle (the sporophyte), produces sporophytes which, like the gametes, are also motile using a set of four flagella to swim (Lee 2008; Guiry and Guiry 2011).

Author(s): Campbell, Dana
Rights holder(s): Campbell, Dana

Morphology

The fronds of Ulva usually grow as sheets, but some species exist in a hollow cylindrical form.  These cylindrical species were previously classified as a distinct genus, Enteromorpha, but have been synonymized with Ulva.  The blade morphology of Ulva is dependent on bacterial composition in the environment (Lee 2008; Hayden et al 2003).

Author(s): Campbell, Dana
Rights holder(s): Campbell, Dana

Size

The blades can grow up to 40 cm long, but are very thin - only 2 cells thick (Lee 2008).

Author(s): Campbell, Dana
Rights holder(s): Campbell, Dana

Ecology

Habitat

Lives in marine environments, and sometimes found in brackish waters in estuaries, however, Ulva needs nitrogen-rich waters.  Ulva attaches to rocks in the mid to low intertidal zone (Lee 2008; Kirby 2001).

Author(s): Campbell, Dana
Rights holder(s): Campbell, Dana

Distribution

Ulva is found worldwide.

Author(s): Campbell, Dana
Rights holder(s): Campbell, Dana

Relevance

Risk Statement

Ulva is considered the main component of "green tide" events in bays especially near large cities in Japan and elsewhere.  Its prolific growth becomes a nuisance, especially in run-off waters containing high nutrient levels.  In these environments it can outcompete other organisms and reduce diversity in benthic communities.  It also creates a nuisance on beaches when it is washed up and decomposes in large amounts as the rotting algae produces hydrogen sulfide gas (Lee 2008; Yabe 2009).

Author(s): Campbell, Dana
Rights holder(s): Campbell, Dana

Uses

Ulva is eaten by humans, although the literature has some disagreement about how tasty and digestible it is.  It is eaten in soups, salads and sushi (Lee 2008 and references within; Kirby 2001).

Author(s): Campbell, Dana
Rights holder(s): Campbell, Dana

Taxonomic Children

Total: 124

Ulva acanthophora (Kützing) Hayden, Blomster, Maggs, P.C. Silva, Stanhope & J.R. Waaland, Ulva anandii Amjad & Shameel, Ulva angusta Setchell & N. L. Gardner, Ulva arasakii Chihara, Ulva armoricana P. Dion, B. de Reviers & G. Coat, Ulva atroviridis Levring, Ulva attenuata (C. Agardh) Naccari, Ulva beytensis Thivy & Sharma, Ulva bifrons Ardré, Ulva brevistipitata V. J. Chapman, Ulva bulbosa Pasilot de Beauvois, Ulva burmanica (Zeller) De Toni, Ulva byssoides Mertens, Ulva californica Wille, Ulva chaetomorphoides (Børgesen) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, Ulva clathrata (Roth) C. Agardh, Ulva coccinea Hudson, Ulva compressa Linnaeus, Ulva conglobata Kjellman, Ulva cornucopiae (Kützing) J. Agardh, Ulva cornucopiae (Lyngbye) Trevisan, Ulva cornuta Lightfoot, Ulva covelongensis V. Krishnamurthy & H. Joshi, Ulva crassa V. J. Chapman, nom. illeg., Ulva crassimembrana (V.J.Chapman) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, Ulva curvata (Kützing) De Toni, Ulva dactylifera Setchell & N. L. Gardner, Ulva denticulata P. J. L. Dangeard, Ulva elegans Gayral, nom. inval, Ulva elminthoides, Ulva enteromorpha Le Jolis, Ulva erecta (Lyngbye) Fries, Ulva expansa (Setchell) Setchell & N. L. Gardner, Ulva fasciata Delile, Ulva fenestrata Postels & Ruprecht, Ulva flexuosa Wulfen, Ulva gelatinosa Kützing, Ulva geminoidea V. J. Chapman, Ulva gigantea (Kützing) Bliding, Ulva grandis Saifullah & Nizamuddin, Ulva hendayensis P. J. L. Dangeard & H. Parriaud, Ulva hookeriana (Kützing) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, Ulva hopkirkii (M'Calla ex Harvey) P. Crouan & H. Crouan, Ulva indica Roth, Ulva intestinalis Linnaeus, Ulva intestinaloides (R.P.T. Koeman & Hoek) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, Ulva intricata Thuillier, ined., Ulva intybacea Lamarck, Ulva javanica Burman, Ulva kylinii (Bliding) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, Ulva lactuca Linnaeus, Ulva lactucaefolia S. F. Gray, Ulva laetevirens Areschoug, Ulva laingii V. J. Chapman, Ulva linearis P. Dangeard, Ulva lingulata A. P. de Candolle, Ulva linkiana (Greville) Trevisan, Ulva linza Linnaeus, Ulva lippii Lamouroux, Ulva litoralis Suhr ex Kützing, Ulva littorea Suhr, Ulva lobata (Kützing) Harvey, Ulva lubrica Roth, Ulva marginata (J. Agardh) Le Jolis, Ulva micrococca (Kützing) Gobi, Ulva myriotrema P. L. Crouan & H. M. Crouan, Ulva neapolitana Bliding, Ulva nematoidea Bory de Saint-Vincent, Ulva ohnoi Hiraoka & Shimada, Ulva olivacea Hornemann, Ulva olivaceum Hornemann, Ulva pacifica Endlicher, Ulva papenfussii Pham-Hoàng Hô, Ulva paradoxa C. Agardh, Ulva parva V. J. Chapman, Ulva parvula Kützing, Ulva patengensis Salam & Khan, Ulva percursa (C. Agardh) C. Agardh, Ulva pertusa Kjellman, Ulva phyllosa (V. J. Chapman) Papenfuss, Ulva popenguinensis P. Dangeard, Ulva porrifolia (S. G. Gmelin) J. F. Gmelin, Ulva procera (K. Ahlner) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, Ulva profunda W. R. Taylor, Ulva prolifera O. F. Müller, Ulva pseudocurvata Koeman & Hoek, Ulva pseudolinza (R.P.T. Koeman & Hoek) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, Ulva pulchra Jaasund, nom. inval., Ulva purpurascens, Ulva quilonensis Sindhu & Panikkar, Ulva radiata (J. Agardh) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, Ulva ralfsii (Harvey) Le Jolis, Ulva ranunculata Kraft & Millar, Ulva reticulata Forsskål, Ulva rhacodes (Holmes) Papenfuss, Ulva rigida C. Agardh, Ulva rotundata Bliding, Ulva rubens, Ulva saifullahii Amjad & Shameel, Ulva scagelii Chihara, Ulva scandinavica Bliding, Ulva sericea Wulfen, Ulva serrata A. P. de Candolle, Ulva simplex (K.L. Vinogradova) Hayden, Blomster, Maggs, P.C. Silva, M.J. Stanhope & J.R. Waaland, Ulva sorensenii V. J. Chapman, Ulva spinulosa Okamura & Segawa, Ulva stenophylla Setchell & N. L. Gardner, Ulva stipitata Areschoug, Ulva sublittoralis Segawa, Ulva subulata (Wulfen) Naccari, Ulva taeniata (Setchell) Setchell & N. L. Gardner, Ulva tenera Kornmann & Sahling, Ulva tetragona A. P. de Candolle, Ulva torta (Mertens) Trevisan, Ulva tuberosa Palisot de Beauvois, Ulva umbilicata S. F. Gray, nom. illeg., Ulva uncialis (Kützing) Montagne, Ulva uncinata Mertens, Ulva uncinata Mohr, Ulva usneoides Bonnemaison, Ulva utricularis (Roth) C. Agardh, Ulva utriculosa C. Agardh, Ulva uvoides Bory de Saint-Vincent, Ulva ventricosa A. P. de Candolle

References

Abbott, I., & Hollenberg G. (1976).  Marine Algae of California. Palo Alto, California: Stanford University Press.
Druehl, L. D. (2000).  Pacific Seaweeds. Madeira Park, British Columbia, Canada: Harbour Publishing.
Graham, L. E., Graham J. M., & Wilcox L. W. (2009).  Algae.
Guiry, M. D., & Guiry G. M. (2011).  AlgaeBase. World-wide electronic publication..
Hayden, H. S., & Waaland J. R. (2002).  PHYLOGENETIC SYSTEMATICS OF THE ULVACEAE (ULVALES, ULVOPHYCEAE) USING CHLOROPLAST AND NUCLEAR DNA SEQUENCES. Journal of Phycology. 38,
Hayden, H. S., & Waaland J. R. (2004).  A molecular systematic study of Ulva (Ulvaceae, Ulvales) from the northeast Pacific . Phycologia. 43, 364-382.
Hayden, H. S., Blomster J., Maggs C. A., Silva P. C., Stanhope M. J., & Waaland J. R. (2003).  Linnaeus was right all along: Ulva and Enteromorpha are not distinct genera. European Journal of Phycology. 38, 277-294.
Hayden, H. S., Blomster J., Maggs C. A., Silva P. C., Stanhope M. J., & Waaland J. R. (2003).  Linneaus was right all along: Ulva and Enteromorpha are not distinct genera. Eur. J. Phycol.. 38, 277-294.
Kirby, A. (2001).  Ulva.
Kozloff, E. N. (1993).  Seashore Life of the Northern Pacific Coast, 3rd printing (with corrections). Seattle: University of Washington Press.
Lee, R E. (2008).  Phycology. New York: Cambridge University Press.
Lee, T. F. (1986).  The Seaweed Handbook. New York: Dover Publications.
Melkonian, M. (1979).  Structure and significance of cruciate flagellar root systems in green algae: Zoospores of Ulva lactuca (Ulvales, Chlorophyceae). Helgoländer Wissenschaftliche Meeresuntersuchungen. 32(4), 425 - 435. Abstract
Nelson, T. A., Lee D. J., & Smith B. C. (2003).  ARE “GREEN TIDES” HARMFUL ALGAL BLOOMS? TOXIC PROPERTIES OF WATER-SOLUBLE EXTRACTS FROM TWO BLOOM-FORMING MACROALGAE, ULVA FENESTRATA AND ULVARIA OBSCURA (ULVOPHYCEAE). Journal of Phycology. 39, 874-879.
Yabe, T., Ishii Y., Yoshimasa Amano, Koga T., Hayashi S., Nohara S., et al. (2009).  Green tide formed by free-floating Ulva spp. at Yatsu tidal flat, Japan. Limnology. 10, 239-245.