BIOTIC Species Information for Cordylophora caspia
|Researched by||Dr Harvey Tyler-Walters & Paolo Pizzolla||Data supplied by||MarLIN|
|Refereed by||This information is not refereed.|
|Scientific name||Cordylophora caspia||Common name||A hydroid|
|MCS Code||D285||Recent Synonyms||Cordylophora lacustris (Allman, 1844)|
|Additional Information||No text entered|
|Taxonomy References||Hayward & Ryland, 1995b, Barnes, 1994, Hincks, 1868, Allman, 1871-1872, Foster-Smith, 2000, Gili & Hughes, 1995,|
||Feeding method||Passive suspension feeder
|Typical food types||Small zooplankton, small crustacea, oligochaetes, insect larvae and probably detritus.||Habit||Attached|
|Bioturbator||Not relevant||Flexibility||High (>45 degrees)|
|Height||Up to 10 cm||Growth Rate||ca 0.05-0.1 mm/hr|
|Adult dispersal potential||See additional information||Dependency||Independent|
|General Biology Additional Information||Growth form
Growth form is highly variable in Cordylophora caspia. The colony of consists of a mass of stolons (hydrorhizae) growing across the surface of the substratum. Growth is apical, with side stolons arising at right angles. Upright hydrocauli bear apical polyps (hydranths), and side branches at 45° (Fulton, 1961).The degree of branching, length and spacing of hydrocauli, cell size, size and shape of polyps and the number and length of tentacles vary with environmental conditions (Fulton, 1962; Kinne, 1970, 1971; Arndt, 1989). For example, colonies have short, polyps that grow directly from the hydrorhiza at 0.5psu; more elongate polyps with longer tentacles and multiply branched uprights at 15psu, but smaller polyps and less branched uprights at 30psu than at 15psu (see Kinne 1970, 1971 for review; Arndt, 1989, Gili & Hughes, 1995). Gaulin et al. (1986) noted that predation by the nudibranch Tenellia fuscata resulted in denser colonies.
|Biology References||Barnes, 1994, Hincks, 1868, Allman, 1871-1872, Gili & Hughes, 1995, Arndt, 1989, Arndt, 1984, Kinne, 1970, Kinne, 1971, Fulton, 1961, Fulton, 1962, Chester et al., 2000, Roos, 1979, Jormalainen et al. 1994), Gaulin et al., 1986,|
|Distribution and Habitat|
|Distribution in Britain & Ireland||The species has a sporadic distribution associated with areas of low salinity within estuaries and brackish lagoons.|
|Global distribution||Found in estuarine, lagoonal and coastal lake habitats in boreal to subtropical waters.|
|Biogeographic range||Not researched||Depth range||Low shore to ca 2m.|
|Migratory||Non-migratory / Resident|
|Distribution Additional Information||Substrata
Most hydroids do not show a high specificity of substrata. Cordylophora caspia has been recorded from a wide variety of hard substrata including rocks, shells and artificial substrata (pilings, harbour installations, bridge supports), floating debris and occasionally from the leaves of reeds (Phragmites) or stalks of water lilies (MBA, 1957; Roos, 1979; Morri & Boero, 1986; Arndt, 1986, 1989; JNCC, 1999; Foster-Smith, 2000).
|Substratum preferences||Artificial (e.g. metal/wood/concrete)
Large to very large boulders
Ria / Voe
Isolated saline water (Lagoon)
Enclosed coast / Embayment
|Biological zone||Lower Eulittoral
|Wave exposure||Very Sheltered
|Tidal stream strength/Water flow||Strong (3-6 kn)
Moderately Strong (1-3 kn)
Weak (<1 kn)
Very Weak (negligible)
|Salinity||Reduced (18-30 psu)
Low (<18 psu)
|Habitat Preferences Additional Information||The distribution of Cordylophora caspia is determined by availability of suitable hard substratum, food availability, range and variability of temperature and salinity. Cordylophora caspia can survive between -10 °C (as resistant dormant stages, menonts) and 35 °C. Colonies tolerate 5 to 35 °C, and reproduce between 10 to 28 °C. It can also survive 0 to 35psu as resistant stages, grow between 0.2 to 30 psu, reproduce between 0.2 to 20psu and possesses the ability to ionic regulate (Kinne, 1971; reviewed by Arndt, 1986, 1989). In nature, well developed colonies are usually found in water of 2 -12psu where tidal influence is considerable or between 2 -6psu where conditions are constant (Arndt, 1989). It may also occur at full salinities, and fast flowing, well oxygenated freshwater containing Ca, Mg, Na Cl and K ions (Fulton, 1962; Arndt, 1989). Arndt (1986, 1989) suggested that respiration, growth and reproduction were optimal between 4-7psu and that food intake was high in comparison to other hydroids so that growth and reproduction rates required for the survival of the species could only occur in eutrophic or hypertrophic waters where food is plentiful. Its marine distribution is probably limited by food availability, competition from Clava spp. or Laomedea spp. and predation e.g. from the nudibranch Tenellia adspersa (as Embletonia pallida) (Arndt, 1989). Cordylophora caspia prefers conditions of low light (Allman, 1871-1872, Arndt, 1989), although light intensity did not affect growth (Fulton, 1963), which probably reflects the settlement preferences of the planula larvae.|
|Distribution References||Hayward & Ryland, 1995b, Barnes, 1994, Hincks, 1868, Allman, 1871-1872, Foster-Smith, 2000, JNCC, 1999, Gili & Hughes, 1995, MBA, 1957, Arndt, 1989, Arndt, 1984, Kinne, 1970, Kinne, 1971, Morri & Boero, 1986, Olenin et al., 2000, Folino, 1999,|
|Reproductive Season||June-August||Reproductive Location||As adult|
|Reproductive frequency||Annual episodic||Regeneration potential||No|
|Life span||See additional information||Age at reproductive maturity||<1 year|
|Generation time||<1 year||Fecundity||See additional information|
|Egg/propagule size||Insufficient information||Fertilization type||Internal|
|Reproduction Preferences Additional Information||Most hydroids (including Cordylophora caspia) are dioecious. The reproductive organs are carried in gonophores. Sperm are released into the sea and eggs are fertilized within the female gonophores where the embryos develop into planulae. Sperm swim towards female gonophores, however, sperm probably have a limited life span and hence a limited range for fertilization of only a few metres. Hence the growth of hydroids in clumps may enhance fertilization rates, albeit at the cost of intraspecific competition. Temperature is critical for stimulating or preventing reproduction in hydroids (see distribution; Gili & Hughes, 1995).
Early seasonal growth from winter dormancy in early spring is rapidly followed by formation of gonophores and sexual reproduction in midsummer followed by active growth in late summer. However, sexual reproductive effort may retard growth (see general biology). Jormalainen et al. (1994) reported that reproduction began in early June, peaked in July (80% uprights with gonophores) and rapidly reduced by August (30% uprights with gonophores). Similar reproductive periods have been reported by other authors (Allman, 1871-1872; MBA, 1957; Roos, 1979; Foster-Smith, 2000). Roos (1979) and Jormalainen et al. (1994) reported that the sex ratio was biased in favour of females.
Each upright branch may bear between 1-3 gonophores each with between 10 - 6 eggs, the number decreasing in autumn (Hincks, 1868; Jormalainen et al., 1994). Therefore, fecundity is dependant on the number of branches and hence the number of gonophores, and in large colonies of 70-2000 polyps (Fulton, 1962), may be high. The larvae are released as planulae and no medusoid stage occurs. However, in some cases the larvae may develop directly into juvenile polyps in the gonophore before release (Bouillon, 1963).
Hydroids may reproduce asexually by budding to from another colony. A common form of asexual reproduction in hydroids is the formation of vertical stolons, which then adhere to adjacent substratum, detach and form another colony (Gili & Hughes, 1995). Hydroids exhibit remarkable powers of regeneration and Cordylophora caspia can be cloned in culture from detached uprights or excised tissue (Moore, 1952;Fulton, 1961, 1962). Asexual reproduction by fission or mechanical fragmentation of the colony may be an important factor in dispersal (Gili & Hughes, 1995).
While uprights have a short, finite life span from about early spring to autumn, no information concerning the life span of the dormant stages (menonts) was found. Unless destroyed by predators or physical damage, the colony may have a long life span (perhaps very long (Gili & Hughes, 1995). The ability to reproduce asexually and regenerate from damaged sections means that although any individual colony may have a finite life span the genetic individual (genet) may be considerably longer lived (Gili & Hughes, 1995).
Rapid growth, budding and the formation of stolons allows hydroids to colonize space rapidly. Hydroids are often the first organisms to colonize available space in settlement experiments (Gili & Hughes, 1995). Planula larvae swim or crawl for short periods (e.g. <24hrs) so that dispersal away from the parent colony is probably very limited (Gili & Hughes, 1995). Fragmentation may also provide another route for short distance dispersal. However, it has been suggested that rafting on floating debris (or hitch hiking on ships hulls or in ship ballast water) as dormant stages or reproductive adults, together with their potentially long life span, may have allowed hydroids to disperse over a wide area in the long term and explain the near cosmopolitan distributions of many hydroid species, including Cordylophora caspia (Gili & Hughes, 1995; Folino, 1999).
|Reproduction References||Hincks, 1868, Gili & Hughes, 1995, MBA, 1957, Arndt, 1989, Fulton, 1961, Fulton, 1962, Roos, 1979, Jormalainen et al. 1994), Bouillon, 1963, Folino, 1999,|