BIOTIC Species Information for Rhodothamniella floridula
|Researched by||Karen Riley||Data supplied by||MarLIN|
|Refereed by||This information is not refereed.|
||Developmental mechanism||Spores (sexual / asexual)
|Reproductive Season||Insufficient information||Reproductive Location||Insufficient information|
|Reproductive frequency||Regeneration potential||No|
|Life span||6-10 years||Age at reproductive maturity||Insufficient information|
|Generation time||Insufficient information||Fecundity||Insufficient information|
|Egg/propagule size||Insufficient information||Fertilization type||Insufficient information|
|Reproduction Preferences Additional Information||Life span
No information was found concerning the longevity of Rhodothamniella floridula. However, it is likely to have a life span of 5-10 years, similar to other red seaweeds, such as Furcellaria lumbricalis.
Dickinson (1963) and Dixon & Irvine (1977) found that asexual Rhodothamniella floridula (as Rhodochorton floridulum and Audouinella floridula respectively) plants bear cruciate tetrasporangia. The tetrasporangia are ovoid and are arranged on the upper parts of the erect axes, occurring singly or in clusters (Dixon & Irvine, 1977). Stegenga (1978) found that tetraspores of cultured Rhodothamniella floridula (as Rhodochorton floridulum) measured up to 35 x 30 µm. He also noted that these were formed under all combinations of temperatures from 4 °C to 16 °C at any length of daylight. A tetrasporophyte, rather than a carposporophyte, of Rhodothamniella floridula (as Rhodochorton floridulum) develops directly from the fertilised carpogonium with only one erect filament and one rhizoid (Lobban & Wynne, 1981, Cole & Sheath, 1990). Stegenga (1978) observed that gametophytes of Rhodothamniella floridula (as Rhodochorton floridulum) were unisexual and possessed a unicellular base from which only one filament arose. It is also known that the subclass Florideophyceae specialise in oogamous reproduction in which the zygote is returned on the female gametophyte, giving rise to complex post-fertilisation development, known as the carposporophyte. Observations on Rhodothamniella floridula (as Rhodochorton floridulum) showed that the tetraspores germinate to give gametangial plants which were small compared with the tetrasporangial phase (Knaggs & Conway, 1964)
Red algae are typically high fecund, but their spores are non-motile (Norton, 1992) and therefore highly reliant on the hydrodynamic regime for dispersal. Stegenga (1978) noted that tetrasporangia germinated in 'rather low numbers', but most abundantly at high temperatures and long days.
Timing of reproduction
Dixon & Irvine (1977) noted that the greatest abundance of tetrasporangia occurred between November and March. Furthermore, Rhodothamniella floridula (as Rhodochorton spp.) are present throughout the year (Laverack & Blackler, 1974). However, Stegenga (1978) found that there were no tetrasporangia present during the winter.
|Reproduction References||Lobban & Wynne, 1981, Stegenga, 1978, Dickinson, 1963, Dixon & Irvine, 1977, Cole & Sheath, 1990, Knaggs & Conway, 1964, Norton, 1992, Laverack & Blackler, 1974,|