Effects of extrinsic abiotic factors on induction of gametogenesis and efficacy of a device for the segregation of non-fused gametes and zygotes in the green alga Ulva lactuca

Abstract Cryptodromia fallax (Latreille in Milbert, 1812) has been serendipitously found again on the island of Mauritius, almost 200 yrs after its discovery. The new material provides new information about the structure of the female sternum, providing stronger evidence that a new genus, Alcockdromiagen. nov., is required. Observations show that this crab cuts out and carries pieces of seaweed in the manner of a paraglider, rather than pieces of sponge normally carried by dromiid crabs. The crab uses Ulva lactuca Linnaeus, a green alga, and Lobophora variegata (J.V. Lamouroux), a brown alga. This discovery shows that the last two prehensile dromiid pereopods, which are used to carry soft camouflage, are multi-purpose, having only minor structural differences allowing them to carry seaweeds.

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Biosorption of Cu(II), Zn(II), Cd(II) and Pb(II) by dead biomasses of green alga Ulva lactuca and the development of a sustainable matrix for adsorption implementation

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2012.01.073 ◽

2012 ◽

Vol 213-214 ◽

pp. 123-132 ◽

Cited By ~ 95

Author(s):

María Mar Areco ◽

Sergio Hanela ◽

Jorge Duran ◽

María dos Santos Afonso

Keyword(s):

Green Alga ◽

Ulva Lactuca

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Comparative ultrastructure of eyespot membranes in gametes and zoospores of the green alga Ulva lactuca (Ulvales)

Journal of Cell Science ◽

10.1242/jcs.50.1.149 ◽

1981 ◽

Vol 50 (1) ◽

pp. 149-164

Author(s):

H. Robenek ◽

M. Melkonian

Keyword(s):

Green Alga ◽

Freeze Fracture ◽

Size Class ◽

Ulva Lactuca ◽

Chloroplast Envelope ◽

Envelope Membrane ◽

Chloroplast Membrane ◽

Green Algal ◽

Male Gametes ◽

Chloroplast Envelope Membrane

Eyespot membranes in zoospores, and male and female gametes of the green alga Ulva lactuca, were studied comparatively by the freeze-fracture technique. The plasmalemma and the outer chloroplast envelope membrane overlying the eyespot lipid globules are specialized in all 3 types of reproductive cells. In the eyespot region the protoplasmic face (PF) of the outer chloroplast envelope membrane contains significantly more intramembraneous particles (IMP) compared to membrane areas outside the eyespot: in female gametes there are 2.5 times more IMP/micrometers 2, in zoospores 3 and in male gametes about 4. Small size-class IMP (4–6 nm diameter) are particularly abundant on both fracture faces of the outer chloroplast membrane, but size-class distribution is not significantly different between membrane areas inside and outside the eyespot region. The total number of IMP/eyespot on the PF of the outer chloroplast membrane was calculated to be 4900 in male gametes, 5500 in female gametes and 11 200 in zoospores. The results are discussed in accordance with the view that these membrane specializations participate in photoreception relating to green algal phototaxis. Evidence is presented that there is a correlation between IMP numbers per eyespot in the outer chloroplast envelope membrane and the different phototactic behaviour of gametes compared to zoospores in Ulva.

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