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Chlorophyta, Green Algae

Boodleopsis pusilla (Collins) Taylor

Chlorophyta, Order: Caulerpales; Family: Codiaceae. In the past, the Boodleopsis was associated with the Cladophorales order; however, as soon as the Boodleopsis was seen to be as a coenocyte with multi-nuclear cells and no walls it was transferred to the Codiaceae family.


The genus has been named Boodleopsis due to its resemblance of the Boodlea alga. The name was given by Murray, G. in 1889. It is apparently the name of a woman, but I could not find proof of this. In English, the word ‘boodle’ is underworld slang for bribery or stolen goods, but no immoral behaviour has been reported on the part of the alga, so far... The species name describes the algal diminutive size.


The alga resembles a bundle of thin, green strands. A microscope is required to identify the genus and its species, at which point the dichotomous (two-horned) branching that characterizes the Boodleopsis is apparent. The various species differ in cellular size, the angle of the dichotomous branching and several other aspects. The branching, as mentioned, is dichotomous and irregular. Additional branching can be seen towards the edge of the thallus.


The strands grow several centimetres in length, and their width is less than 1 mm.


The thallus is green.

Special features

Without a microscope, it is easy to confuse the Boodleopsis with the Cladophora, the Chaetomorpha or other species found along the shore. The Boodleopsis is characterized by its dichotomous branching. The Cladophora, on the other hand, is regularly branched, usually in one direction, and the Chaetomorpha does not branch at all. A useful field distinction is that the Boodleopsis thallus is often curled around itself, but definitive identification requires a microscope to ascertain that there are no cell walls, not even in the vicinity of the branching.


The individuals found in the Shikmuna area (near Haifa) were collected near the low-tide line at the bottom of the intertidal zone. Lately (1998) individuals were found breeding in the Mikhmoret Marine Academy aquarium.

Biology and reproduction

The life cycle of some species of Boodleopsis have been researched and found to be similar. The archegonium (female reproductive organs) and the antherudium (male reproductive organs) produce two zoospores each and are generated upon the same thallus. As mentioned, the Boodleopsis is a multi-nuclear alga without cell walls, in which the nuclei are relatively small, and the amyloplast usually containing more than one grain of starch. Genealogically, the genus is related to the Bryopsis and to the Flabellia, and may be the ancestor or primordial sibling of both.

Seasonality and distribution

As far as is known, Boodleopsis individuals were first identified along the Israeli coast and in the Mediterranean

at the time of preparing this book (I found some individuals along the Monaco coast). However, this does not indicate rarity or a novel appearance, but rather lack of information. The individual photographed was found in the intertidal zone of the Shikmuna beach. In other places around the world, Boodleopsis has been reported in deep water (35 m) as well as in the intertidal zone. The species’ distribution includes the United States coast, Brazil and the Pacific Islands.

Additional species

The Boodleopsis pusilla found here is very similar to the Boodleopsis pusilla (Collins) Taylor, found in the Caribbean Islands. It seems that they are the same species.

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