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Potentially Misidentified Species:
Identification of any Spirorbis specimens to species level is
difficult, even for trained taxonomists. The literature abounds with
questionable or errant species designations.
II. HABITAT AND DISTRIBUTION
Regional Occurrence:
The genus Spirorbis as a whole occurs across a very broad distributional range of
latitudes. For example, specimens identified as S. borealis
have been collected from Iceland south to Florida. Species-specific
distributional information is currently lacking.
IRL Distribution:
Spirorbis occurs on suitable macrophyte habitats and some other hard substrata throughout the IRL.
III. LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan:
Most species of Spirorbis have body lengths of around 3 mm.
Abundance:
NOAA NBI collection records from Florida
Bay and adjacent coastal waters reveal field densities of Spirorbis
to vary between 25 and 1,600 individuals/m2, with most records
reporting densities of 100/m2 or less.
Reproduction:
A survey of the literature indicates that reproductive strategies differ
somewhat among the members of genus Spirorbis. Much of the genus
appears to exhibit hermaphroditism with some species self-fertilizing and
others cross-fertilizing, and most protectively brood their eggs and larvae
(Bergan 1953, Gee and Williams 1965, Potswald 1968, Ghiselin 1969). Some
species appear to rely on external fertilization while others appear to
utilize internal fertilization (Potswald 1968).
Reproductive seasonality appears variable among species and geographical
locations as well. Surveys by Rothlisberg (1974) indicate La Jolla, CA,
populations of S. marioni produce and brood eggs year-round, and
those by Mook (1983) suggest Indian River Lagoon Spororbis spp.
reproduce throughout the year as well. Seasonal reproductive peaks appear
correlated with water temperature, and periodic peaks in spawning and
larval release may correlate with tidal extremes (Rothlisberg 1974).
utilize internal fertilization (Potswald 1968).
In Spirorbis spirorbis (Daly and Golding 1977, Rice 1978) and possibly other Spirornis species, sperm
storage and delayed fertilization at the time of egg release obviate
the need for synchronized spawning in functional males and females
within the population.
Embryology:
Spirorbis spirillum broods its eggs and larvae until the larvae are
released to the water column for a brief (minutes) period before settling
(Dirnberger 1990, Bell et al. 2001). Potswald (1968) notes that brood
protection within genus Spirorbis occurs either within the parental
tube or within a modified opercular structure. Larvae accumulate
environmental calcium and secrete it at settlement during tube formation
(Nott and Parkes 1975).
Mook (1983) reports the year-round settlement of large numbers of
Spirorbis spp. in the Indian River Lagoon. Mook (1981) noted a
higher incidence of settlement onto experimental tiles that had been
recently scraped clean and suggested these tiles suitably mimicked
naturally-occurring freshly opened primary space that the species is
adapted to rapidly colonize.
IV. PHYSICAL TOLERANCES
Temperature:
The genus as a whole occurs across a very broad range of temperatures.
Information regarding the temperature tolerance of individual species of
Spirorbis is scarce.
Salinity:
Examination of NOAA NBI collection records for Spirorbis in Florida Bay and adjacent coastal
waters reveals most animals were collected from oceanic salinities.
Populations occurring elsewhere in Florida (e.g., in the IRL) persist at
estuarine salinities somewhat lower than these, but there is little
published information indicating the ability of these animals to withstand
extreme salinity fluctuations.
V. COMMUNITY ECOLOGY
Trophic Mode:
Like most serpulid polychaetes, Spirorbis are filter-feeding
animals. They use a crown of stiff tentacles to capture particles from the
surrounding water.
Predators:
Spirorbis and other seagrass and macrtoalgal epibiota is
opportunistically preyed upon by various grazers of marine macrophytes
(Wressing and Booth 2007). The calcareous tube dwellings offers a limited
degree of protection from smaller or less robust predators.
Associated Animals:
Active preference by settling Spirorbis for surfaces coated by
microbial films has been reported (Walters et al. 1997). DeSilva (1962)
reports preferential settlement of S. tridentatus onto stones with
bio-organic films. Several other authors have reported preferences of
settlement-stage Spirorbis for specific macroalgae (e.g., Stebbing
1972, MacKay and Doyle 1978, Al-Ogily 1985). Fenical (1993) notes that
these associations may be associated exclusively with the macroalgae, with
the presence of bacteria on algal surfaces, or both. The presence of adult
conspecifics has also been shown to increase settlement rates in S.
borealis and S. pagastecheri (Knight-Jones 1951, Walters et al.
1997).
Mook (1983) reports that Spirorbis sp. settled onto the tests (body
surface) of the sea squirt Styela plicata during the course of field
experiments conducted in the Indian River Lagoon.
Spirorbis spp. has also been reported as an epibiont on sick and
injured sea turtles in southwest Florida (Thompson 1997).
Habitats:
Bell et al. (2001) describe Spirorbis spirillum as a tube-building
epibiont typically found attached to seagrass blades. Turtle grass
(Thalassia testudinum) and manatee grass (Syringodium
filiforme) are the most heavily colonized of Florida's seagrass
species. Other species of Spirorbis typically attach to fucoid
brown algae, e.g., as reported for S. borealis in the vicinity of
Woods Hole, MA (Schively 1897). Spirorbis also occurs on pelagic
Sargassum macroalgae in the Guld Stream (Weis 1968).
Less commonly, Spirorbis settles onto red mangrove (Rhizophora
mangle) prop roots (Bingham 1992).
Dirnberger (1990) reports that Spirorbis spirillum larvae
disproportionately settle on the bases of growing Thalassia blades
and actively avoid epiphytic algae associated with the distal portion of
the blades. Bell et al. (2001) report that S. spirillum densities
on Thalassia seagrass blades was reduced at grassbed edges compared to the
seagrass bed interior, and suggested hydrodynamic alteration of food supply
or larval recruitment as explanations.
VI. SPECIAL STATUS
Special Status:
None.
Economic/Ecological Importance:
Although the overall ecological importance of Spirorbis is
not known, it is a broadly distributed and diverse polychaete
genus. The Integrated Taxonomic Information System (ITIS)
recognizes some two dozen valid species within
the genus.
VII.
REFERENCES
Al-Ogily SM. 1985. Further experiments on larval behavior of
the tubicolous polychaete Spirorbis inornatus L'Hardy &
Quivreux. Journal Experimental Marine Biology and Ecology.
86:285-298.
Bell SS, Brooks RA, Robbins BD, Fonseca MS, and MO Hall. 2001.
Faunal response to fragmentation in seagrass habitats:
Implications for seagrass conservation. Biological Conservation
100:115-123.
Bergen P. 1953. On the anatomy and reproduction biology in
Spirorbis Daudin. Nytt Mag. Zool., 1:1-26.
Bingham BL. 1992. Life histories in an epifaunal community:
Coupling of adult and larval processes. Ecology Vol 73(6):
2244-2259.
Daly JM and DW Golding. 1977. A description of the spermatheca
of Spirorbis (L.) (Polychaeta:Serpulidae) and evidence
for a novel mode of sperm transmission. Journal Marine
Biological Association 57: 219-227.
DeSilva PHDH 1962. Experiments on the choice of sub- strate by
Spirorbis larvae (Serpulidae). Journal Experimental
Biology 39: 483-490.
Dirnberger JM. 1990. Benthic determinants of settlement for
planktonic larvae: Availability of settlement sites for the
tube-buildng polychaete Spirorbis spirilum (Linneaus)
settling onto seagrass blades. Journal of Experimental Marine
Biology and Ecology 140:89-105.
Fauchald K 1977. The Polychaete Worms. Definitions and Keys to
the Orders, Families and Genera. Natural History Museum of Los
Angeles County, in conjunction with the Allan Hancock
Foundation, University of Southern California Science Series
28. 199 p.
Fenical W. 1993. Chemical studies of marine bacteria:
developing a new resource. Chem. Rev. 93: 1673-1683.
Gee JM and GB Williams. 1965. Self and cross-fertilization in
Spirorbis borealis and S. pagenstecheri. Journal
Marine Biological Association United Kingdom, 45: 275-285.
Ghiselin MT. 1969. The evolution of hermaphroditism among
animals. Quarterly Review of Biology, Vol. 44(2), pp. 189-208.
Gibson RN, Atkinson RJA, and JDM Gordon. 2005. Oceanography
and Marine Biology: An Annual Review. CRC Press. 600 p.
Hedley RH. 1956. Studies of serpulid tube formation. II. The
calcium secreting glands in the peristomium of
Spirorbis, Hydroides, and Serpula. Quarterly
Journal Microscopic. Science. 97: 421-427.
Ivany LC, Portell RW, and DS Jones. 1990. Animal-plant
relationships and paleobiogeography of an Eocene seagrass
community from Florida. PALAIOS, Vol. 5,(3), pp. 244-258.
Knight-Jones EW 1951. Gregariousness and some other aspects of
the settling behavior of Spirorbis. Journal Marine
Biological Association, United Kingdom. 30: 201-222.
MacKay TFC and Doyle RW. 1978. An ecological genetic analysis
of the settling behavior of a marine polychaete: Causes of
settlement patterns in a serpulid polychaete I. Probability of
settlement and gregarious behavior. Heredity 40: 1-12.
Mook DH. 1981. Effects of disturbance and initial settlement on
fouling community structure. Ecology, Vol. 62(3): 522-526.
Mook D. 1983. Responses of common fouling organisms in the
Indian River, Florida, to various predation and disturbance
intensities. Estuaries 6:372-379.
Nott JA and KR Parkes. 1975. Calcium accumulation and secretion
in the serpulid polychaete Spirorbis spirorbis at
settlement. Journal Marine Biological Association, United
Kingdom 55: 911-923.
Potswald HE. 1968. The biology of fertilization and brood
protection in Spirorbis (Laeospira) morchi. Biological
Bulletin, Vol. 135(1) pp. 208-222.
Rice SA. 1978. Spermatophores and sperm transfer in spionid
polychaetes: Transactions of the American Microscopical
Society, Vol. 97(2 ) pp. 160-170.
Rothlisberg PC. 1974. Reproduction in Spirorbis
(Spirorbella) marioni Caullery & Mesnil
(polychaeta: Serpulidae). Journal of Experimental Marine
Biology and Ecology 15:285-297.
Schively, MA. 1897. The anatomy and development of Spirorbis
borealis Proceedings of the Academy of Natural Sciences of
Philadelphia, Vol. 49 pp. 153-160.
Shulman JSW. 1968. Fauna associated with pelagic sargassum in
the Gulf Stream. American Midland Naturalist, Vol. 80 (2) pp.
554-558.
Stebbing ARD 1972. Preferential settlement of a bryozoan and
serpulid larvae on the younger parts of Laminaria fronds.
Journal Marine Biological Association, United Kingdom. 52:
765-772.
Thompson M. 1997. Epibionts on the carapaces of sick and
injured sea turtles in southwest Florida during a time of
frequent red tide. Unpublished undergraduate thesis, New
College, FL.
Walters MG, Hadfield, KA. del Carme. 1997. In the importance of
larval choice and hydrodynamics in creating aggregations of
Hydroides elegans (Polychaeta: Serpulidae) vertebrate
Biology Vol. 116 (2) pp. 102-114.
Wressnig A and DJ Booth. 2007. Feeding preferences of two
seagrass grazing monacanthid fishes. Journal of Fish
Biology 71:272-278.
Report by:
J. Masterson, Smithsonian Marine Station
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