| Pterocladiophilaceae | |
|---|---|
Scientific classification  | |
| (unranked): | Archaeplastida |
| Division: | Rhodophyta |
| Class: | Florideophyceae |
| Order: | Gracilariales |
| Family: | Pterocladiophilaceae Kung Chu Fan & George F. Papenfuss 1959: 38 [1] |
The Pterocladiophilaceae is a small family of red algae containing 2 (or 3) genera of thallus parasitic algae.
The family Pterocladiophilaceae was originally established by Fan & Papenfuss (1959: 38) to accommodate their newly named genus and species, Pterocladiophila hemisphaerica, a parasite on Pterocladia lucida (R. Brown ex Turner) J. Agardh in New Zealand. This parastitic alga, which differs from all other parasitic red algae in having zonately divided tetrasporangia, was tentatively assigned to the Cryptonemiales. Fredericq & Hommersand (1990a), as an outgrowth of their detailed morphological study of Holmsella pachyderma(Reinsch) Sturch, a parasite algae feeding on Gracilaria and Gracilariopsis in Great Britain and Ireland that had been assigned to the Choreocolacaceae family, noted that it had a lot of similarities among HolmsellaSturch, GelidiocolaxGardner, and Pterocladiophila. These various similarities include the pattern of vegetative cell division, catenate (chain-like) spermatangia, two-celled carpogonial branch, and the apparent absence of an auxiliary cell. Fredericq & Hommersand grouped these three genera in the Pterocladiophilaceae family, arguing that the cruciate division of tetrasporangia in Gelidiocolax and Holmsella was not a serious objection to uniting these genera with Pterocladiophila. Moreover, on the basis of certain features of spermatangial initiation, gonimoblast development, and the pattern of concavo-convex divisions of apical and cortical cells, they assigned the family to the Gracilariales. [2] [3]
Pterocladiophila hemisphaericaK.-C.Fan & Papenfuss has shown due to Dna analysis, to be within the Ceramiales order, but the parasite was grouped with support as sister to the Gracilariales order. [4]
Figures in brackets are approx. how many species per genus. [5]
Note, PterocladiophilaK.-C.Fan & Papenfuss, 1959 is not accepted as a species by the GBIF. [5] It has a sole species Pterocladiophila hemisphaericaK.-C.Fan & Papenfuss, that was originally described from New Zealand, and has also been recorded from the Caribbean (Stegenga and Vroman 1986). The species is accepted by AlgaeBase, [6] and WoRMS. [7]
They feed on members of the Gelidiaceae family or Gracilaria species of algae, forming small, white to pigmented, hemispherical to verrucose, pustules (raised structure containing necrotic inflammatory cells). [3] They basally penetrate the tissue of the host and protrude above the host's surface. [8]
They are minute, generally more or less spherical (in shape), [8] They have an internal structure of branched, endophytic, rhizoidal filaments pit-connected to host cells, and the pustules of outer, anticlinal, cortical chains and inner larger-celled, multinucleate, medullary cells with numerous secondary pit-connections. [3]
Reproduction is carried out by Gametangial thalli dioecious. The Carpogonial branches (female parts) are 2-celled, [8] borne on a supporting cell in a cortical filament, with a straight trichogyne (slender, hair-like cell which receives the fertilizing particles). The auxiliary cells are absent; fertilized carpogonium possibly fusing with adjacent vegetative cells and developing the gonimoblast directly, consisting of horizontal filaments fusing with vegetative cells and clusters of erect filaments bearing chains of carposporangia, interspersed among cortical filaments; pericarp absent. Spermatangia formed in chains from surface cortical cells, cut off by intercalary divisions from initial cells. [3]
Tetrasporangia scattered in the cortex or in pits, cruciately or zonately divided. [3] The spermatangia are produced in chains, cut off transversely at upper end of spermatangial parent cell. [8]
Gracilaria is a genus of red algae (Rhodophyta) notable for its economic importance as an agarophyte, as well as its use as a food for humans and various species of shellfish. Various species in the genus are cultivated among Asia, South America, Africa and Oceania.
Ceramium is a genus of Ceramium algae. It is a large genus with at least 15 species in the British Isles.
Red algae, or Rhodophyta, are one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity.
Hildenbrandia is a genus of thalloid red alga comprising about 26 species. The slow-growing, non-mineralized thalli take a crustose form. Hildenbrandia reproduces by means of conceptacles and produces tetraspores.
Claudea is a marine red alga genus.
Polysiphonia atlantica is a small filamentous species of red marine algae Rhodophyta. The thalli form small tufts up to 3 cm long. The axes are ecorticate consisting of axial cells surrounded by four periaxial cells.
Sirodotia huillensis Skuja is a freshwater red algal species belonging to the family Batrachospermaceae. This species mostly reported from high altitude forest streams.
Polysiphonia denudata is a small red alga, Rhodophyta, growing as tufts up to 20 cm long without a main branch axis.
Polysiphonia devoniensis is a species of marine algae. It is a small red alga in the Division Rhodophyta. It is a species new to science only described recently and first published in 1993.
Polysiphonia elongella Harvey in W.J. Hooker is a branched species of marine red algae in the genus in the Polysiphonia in the Rhodophyta.
Polysiphonia fibrata is a species of Polysiphonia that grows as small dense tufted and finely branched marine alga in the Rhodophyta.
Polysiphonia fibrillosa (Dillwyn) Sprengel is a species of marine red alga in the Rhodophyta.
Melanothamnus harveyi, Harvey's siphon weed, is a small marine red alga in the division of Rhodophyta.
Vertebrata thuyoides is a small marine algae in the Division Rhodophyta.
Ceramium flaccidum is a small red marine alga in the Division Rhodophyta.
Ceramium cimbricum is a small red alga in the division Rhodophyta.
Ceramium deslongchampsii is a small marine red alga in the Division Rhodophyta.
Ceramium shuttleworthianum is a small marine red alga.
The Gracilariaceae is a small family of red algae containing several genera of agarophytes. It has a world-wide distribution. 24 species are found in China, and 6 species are found in Great Britain and Ireland. It is found in Australia and Chile.
Naccariaceae is a family of red algae in the order Bonnemaisoniales, with 3 monotypic genera that are found in both the Pacific and Atlantic Oceans.