BIOTIC

BIOTIC Species Information for Rhodothamniella floridula

Researched by

Karen Riley

Data supplied by

MarLIN

Refereed by

This information is not refereed.

Reproduction/Life History

Reproductive type

Oogamous

Developmental mechanism

Spores (sexual / asexual)

Reproductive Season

Insufficient information

Reproductive Location

Insufficient information

Reproductive frequency

Regeneration potential

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

Larvae/Juveniles
Larval/Juvenile dispersal potential	Insufficient information	Larval settlement period	Insufficient information
Duration of larval stage	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.

Reproductive type
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)

Fecundity
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,