Cystoseira baccata is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of brown seaweed in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Fucaceae

Fucaceae

Fucaceae are a family of brown algae. There are seven genera in the family, most notably Fucus, which includes several common seaweeds....

. It is found in the north east Atlantic, the Baltic Sea and the Mediterranean Sea. The species name baccata means "berry-like" and refers to the small air bladders.

Taxonomy

This species was known as Cystoseira fibrosa until 1950, when P.C.Silva pointed out that it had first been described in 1768 by S.G.Gmelin

Samuel Gottlieb Gmelin

Samuel Gottlieb Gmelin was a German physician, botanist and explorer.- Background :Gmelin was born at Tübingen in a well known family of naturalists. His father was Johann Conrad Gmelin, an apothecary and surgeon. His uncle was Johann Georg Gmelin...

, who had found the lectotype

Lectotype

In botanical nomenclature and zoological nomenclature, a lectotype is a kind of name-bearing type. When a species was originally described on the basis of a name-bearing type consisting of multiple specimens, one of those may be designated as the lectotype...

 in the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

 and called it Fucus baccatus. His original material cannot now be found but his illustration serves to identify the species.

Description

C. baccata is a tough, leathery seaweed of a yellowish or brownish colour. It is a perennial, each year growing new branches up to 50 cm long from a dark brown, cone-shaped base. The main axis is flattened and has a cross section of 1 cm x 0.5 cm. The side branches are alternate and cylindrical, being arranged in a pinnate fashion. The smallest branches are fine and wiry. There are small, lemon-shaped aerocysts or air bladders on the smaller branches. Usually these are single but sometimes there are several in a chain. When the lateral branches are shed in the winter, the base of the main axis can be seen to have a zigzag shape caused by the deciduous primary laterals. The receptacles are terminal, up to 5 cm long, cylindrical with knot-like swellings and covered with tiny threads. In the spring when new lateral shoots grow there are few if any aerocysts. By the autumn they are more numerous and noticeable.

Distribution and habitat

C. baccata occurs from the Baltic Sea

Baltic Sea

The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

 south to the Mediterranean Sea

Mediterranean Sea

The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

, the Canary Islands

Canary Islands

The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...

, Mauritania

Mauritania

Mauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...

 and Western Sahara

Western Sahara

Western Sahara is a disputed territory in North Africa, bordered by Morocco to the north, Algeria to the northeast, Mauritania to the east and south, and the Atlantic Ocean to the west. Its surface area amounts to . It is one of the most sparsely populated territories in the world, mainly...

. It is commonest in France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 and Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

, and in the British Isles

British Isles

The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...

 it is mostly found in the Channel Islands

Channel Islands

The Channel Islands are an archipelago of British Crown Dependencies in the English Channel, off the French coast of Normandy. They include two separate bailiwicks: the Bailiwick of Guernsey and the Bailiwick of Jersey...

, the south coast of England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 and the west coast of Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

. It is usually found on the lower shore and the sublittoral zone attached to rocks or higher up the shore in deep pools with sandy bases.

Biology

The conceptacle

Conceptacle

Conceptacles are specialised cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole. Conceptacles are present in Corallinaceae, and Hildenbrandiales, as well as the brown Fucales. In the Fucales there is no...

s of C. baccata are specialised reproductive cavities and form in the receptacles which are fertile from June until the autumn. Inside the conceptacles are antheridial hairs on which the antheridia

Antheridium

An antheridium or antherida is a haploid structure or organ producing and containing male gametes . It is present in the gametophyte phase of lower plants like mosses and ferns, and also in the primitive vascular psilotophytes...

 or male gamete

Gamete

A gamete is a cell that fuses with another cell during fertilization in organisms that reproduce sexually...

s develop. About forty oospheres

Ovum

An ovum is a haploid female reproductive cell or gamete. Both animals and embryophytes have ova. The term ovule is used for the young ovum of an animal, as well as the plant structure that carries the female gametophyte and egg cell and develops into a seed after fertilization...

 or female gametes also develop in each conceptacle. The antheridia are liberated first through a pore called the ostiole

Ostiole

An ostiole is a small hole or opening through which algae or ascomycetal fungi release their mature spores. The term is also used in higher plants, for example to denote the opening of the involuted fig inflorescence through which fig wasps enter to pollinate and breed....

 and accumulate around it in an orange mound. The ripe oospheres are then liberated and are fertilised externally. They become more rounded and sink to the sea floor where segmentation starts within a few hours. Four primary rhizoid

Rhizoid

Rhizoids are thread-like growths from the base or bottom of a plant, found mainly in lower groups such as algae, fungi, bryophytes and pteridophytes, that function like roots of higher plants ....

s develop from each and the lateral branches soon begin to grow.