Invasion History

First Non-native North American Tidal Record: 2017
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 2017

General Invasion History:

The brittle star Ophiothela mirabilis was described from the Pearl Islands, Panama (Verrill 1867), and is known from Baja California, Mexico to Panama and the Galapagos Islands (Alvarado et al. 2010; Galván-Villa et al. 2017; U.S. National Museum of Natural History 2019). It is one of a group of epizoic brittle stars that inhabit sessile organisms, including sponges, corals, gorgonians, bryozoans, and tunicates (Clark 1976; Mantelatto et al. 2016). Very similar, possibly indistinguishable, species of Ophiothela exist in Australia, and elsewhere in the Indo-Pacific, so it is possible that this species has a much larger native range (Clark 1976; Hendler et al. 2012). In 2000, this brittle star was reported from Ilha do Pai, Rio de Janeiro State, Brazil, the first record of this genus in the Atlantic Ocean. Its published range now extends from Santa Catarina State, Brazil (-26.3838S) to St. Vincent in the Caribbean (13.1783 N, Mantelatto et al. 2016; Lawley et al. 2018). The first records of this brittle star in US Atlantic waters are from October 2018, when it was reported in Dania Beach, FL and later off nearby Palm Beach (26.67 N), (Daniel Wesley, personal communication, USGS Nonindigenous Aquatic Species Program 2019; Glynn et al. 2019). This brittle star could be easily transported in the fouling communities of ships. It can reproduce by fission and can rapidly reach high densities on bryozoans, and sponges. Most species in the family Ophiuroidea can reproduce sexually, and have planktonic larvae, but sexual reproduction has not been determined for O. mirabilis (Hendler et al. 2012). 

North American Invasion History:

Invasion History on the East Coast:

Ophiothela mirabilis has been reported from Dania Beach, Florida in October 2018 (Glynn et al. 201), and from a reef at 18 m depth off Palm Beach, Florida (1/13/19, Daniel Wesley, personal communication, USGS Nonindigenous Aquatic Species Program 2019). In later sampling it was found from Hillsboro Beach to Fisher Island, Miami (Glynn et al. 2020. The brittle star has been found on eight species of octocorals in Florida but rarely on other hosts, including algae, sponges, and hydroids (mGlynn et al. 2020). This brittle star is small (disk diameter 1-6 mm) but it is bright yellow-orange and has become very numerous due to asexual reproduction (Hendler.et al. 2012; Glynn et al. 2019), so could be noticed by divers. Given its wide invaded range in the Atlantic, it can be expected to extend its range on the Atlantic Coast of Florida and in the Gulf.

Invasion History Elsewhere in the World:

As noted above in 2000, this brittle star was reported from Ilha do Pai, Rio de Janeiro State, Brazil, this was the first record of this genus in the Atlantic Ocean. Its published range now extends from Santa Catarina State, Brazil (-26.3838S) to St. Vincent in the Caribbean (13.1783 N, Mantelatto et al. 2016; Lawley et al. 2018). It has been reported from at least 12 locations of 40 degrees of latitude from Parana, Brazil to St. Vincent in the Caribbean (Mantelatto et al. 2016; Lawley et al. 2018).


Description

The brittle star Ophiothela mirabilis is relatively small with a disk diameter of 1-6 mm, and arms of 5-15 mm. There are usually six arms, but since the species reproduces by fission, lost arms can regenerate, thus the numbers and lengths of arms can vary. The dorsal side of the disk is twelve-lobed, and mostly covered by twelve large oval radial shields. The disk and shields are covered by skin, which is studded with rounded granules (Verrill 1867; Hendler.et al. 2012; Hendler and Brugneaux 2013; Lawley et al. 2018). On the ventral (oral) side of the disk, the six jaws are studded with a cluster of ten rounded dental papillae. Oral papillae are absent. The lateral arm plates have five or six thorny arm spines with hooks at the tip, the middle spine is usually the longest. The ventral arm plates are about as long as they are broad and have rounded edges. Brittle stars from the Eastern Pacific vary in color. Three color morphs were found in the Atlantic: bright yellow-orange, beige, and mottled orange, and beige, with proportions varying by location. Most of the animals at Dania Beach were beige, while all of the animals at Fisher Island, Miami, were orange. The orange and beige color morphs represent two genetic clades. The orange ones are in Clade A and are from Florida, Guyana, Brazil and O. danae in Australia, which is considered a synonym by the WoRMS database, Appeltans et al. 2021). The beige color morph is from Florida, Peru, and Pacific Mexico. The occurrence of at least two morphs and clades suggest at least two separate introductions (Glynn et al. 2020). Ophiothela mirabilis has an epizoic lifestyle, occurring on sponges, corals, gorgonians, bryozoans, and tunicates (Mantellato et al. 2016). In Florida, they were found primarily in octocorals. An increase, in soft octocorals is associated with the decline of hard scleractinian corals (Glynn et al. 2020). Atlantic identifications of O. mirabilis are somewhat tentative, and sometimes assigned 'cf'.mirabilis The genus had been considered confined to the Indo-Pacific, and the Eastern Pacific O. mriabilis is not easily distinguishable from the Australian O. hadra, and could possibly be conspecific (Clark 1976).


Taxonomy

Taxonomic Tree

Kingdom:   Animalia
Phylum:   Echinodermata
Class:   Stelleroidea
Subclass:   Ophiuroidea
Order:   Amphilepidida
Family:   Ophiotrichidae
Genus:   Ophiothela
Species:   mirabilis

Synonyms

Ophiothrix mirabilis (Verrill, 1867)
Ophiothela danae (Koehler, 1898)
Ophiothela caerulea (H. L. Clark, 1915)
Ophiothela coerulea (H. L. Clark, 1915)
Ophiothela dividua (yon Martens, 1879)
Ophiothela hadra (H. L. Clark, 1915)
Ophiothela involuta (Koehler, 1898)
Ophiothela insidcola (Duncan, 1879)

Potentially Misidentified Species

Ophiactis savignyi
Ophiactis savignyi is somewhat larger than O. mirabilis, with a disk diameter of 2-5 mm and six arms 13-20 mm in length. There are two genetic lineages, Lineage A, tropical-cosmopolitan and cryptogenic in the Atlantic, and Lineage B, introduced from the Indo-Pacific. Colors are variable, and the arms are marked with dark bands (Roy and Sponer 2002; Hendler et al. 2013)..

Ophiomyxa flaccida
Ophiomyxa flaccida (Slimy Brittle Star) can be bright orange, but its color varies to off-white, green, or gray. It is much larger with a disk up to 20 mm across. It is native from Florida to Venezuela (Kaplan 1988).

Ecology

General:

The brittle star Ophiothela mirabilis is epizoic, occurring in and on colonies of sponges, corals, bryozoans, and tunicates. Its known mode of reproduction is by fission, dividing into two animals, which means that many animals have varying number or length of arms. The usual number is six, allowing even division, but numbers of arms can change due to predation and regeneration (Clark 1976; Hendler et al. 2012). It is possible that O. mirabilis can also reproduce sexually and produce a planktonic larva as in other ophiuroids (e.g., the invasive Ophiactis savignyi, Hendler et al. 2012).

Ophiothela mirabilis is known from tropical and subtropical habitats from Mexico to the Galapagos, and southern Brazil to southern Florida (Galván-Villa et al. 2017; Hendler et al. 2012; Daniel Wesley, personal communication, USGS Nonindigenous Aquatic Species Program 2019). It was absent in low-salinity surface waters at Les Battures, French Guiana, but present in deeper, more saline layers (Hendler et al. 2013). It has been reported from rocky substrates and a wide variety of sessile animals, including sponges, gorgonians, soft corals, and bryozoans (Hendler et al. 2012; Galván-Villa et al. 2017; Thé de Araújo et al. 2018; Fortunato et al. 2021). In Ilha Grande Bay, Brazil, this brittle star was found on 29 species of animals, including sponges, five species of tunicates, and even the tail of a seahorse (Hippocampus reidi) (Mantelatto et al. 2016). Epizoic brittle stars feed on settled detritus, filamentous algae, and mucus, and/or suspension-feed on plankton. Apparently, these ophiuroids do not feed on their hosts (Clark 1976; Glynn et al. 2020). In its native range it often has camouflage colors, but the bright yellow orange morph invading in the Atlantic could indicate a noxious taste or toxin (Mantelatto et al. 2016).

Food:

Phytoplankton, Zooplankton, mucus, detritus

Trophic Status:

Deposit Suspension Feeder

DepSusFed

Habitats

General HabitatMarinas & DocksNone
General HabitatRockyNone
General HabitatBedrockNone
General HabitatVessel HullNone
Tidal RangeSubtidalNone
Vertical HabitatEpibenthicNone


Tolerances and Life History Parameters

Maximum Length (mm)36Disk diameter + 2 arms (Verrill 1867; Hendler.et al. 2012; Lawley et al. 2018).
Broad Temperature RangeNoneSubtropical-Tropical
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

Ophiothela mirabilis has been seen in high densities and conspicuous yellow-orange masses on gray or purple gorgonians and other fouling organisms. These dense aggregations could have negative impacts on the hosts by interfering with feeding (Hendler et al. (2012; Mantelatto et al. 2016). Experimental studies of isolated octocoral branches found that high densities of O. mirabilis can reduce the number of extended polyps, possibly interfering with feeding of the corals, but did not damage polyps or prevent growth. Brittle stars can benefit octocorals by removing detritus, providing some benefits (Glynn et al. 2021).

Regional Impacts

CAR-INorthern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern FloridaEcological ImpactCompetition
In the Palm Beach Lagoon, Florida, the introduce Brittlestar Ophiothela mirabilis is reducing the abundance of the native suspension-feeding epibenthic ctenophore, Coeloplana waltoni through interference competition.
S196_CDA_S196 (Cape Canaveral)Ecological ImpactCompetition
n the Palm Beach Lagoon, Florida, the introduce Brittlestar Ophiothela mirabilis is reducing the abundance of the native suspension-feeding epibenthic ctenophore, Coeloplana waltoni through interference competition.

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
SEP-H None 1877 Native Estab
NEP-IX None 0 Native Estab
NEP-VIII None 0 Native Estab
SEP-Z None 0 Native Estab
SA-II None 2000 Def Estab
SA-III None 2004 Def Estab
CAR-IV None 2011 Def Estab
CAR-VI None 2013 Def Estab
CAR-III None 2013 Def Estab
SA-IV None 2014 Def Estab
CAR-I Northern Yucatan, Gulf of Mexico, Florida Straits, to Middle Eastern Florida 2018 Def Estab
S196 _CDA_S196 (Cape Canaveral) 2018 Def Estab
NEP-VII None 0 Native Estab
S200 Biscayne Bay 2017 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude

References

2011-2015 World Registry of Marine Species. http://www.marinespecies.org/index.php

Derviche, Patrick; da Cunha Lana, Paulo (2022) The effects of the nonnative brittle star Ophiothela mirabilis Verrill, 1867 on the feeding performance of an octocoral host in a southwestern Atlantic rocky shore, Biological Invasions 24(9): 2821 - 2833

Fortunato, Humberto F.M.; Lôbo-Hajdu, Gisele (2021) Quantification of the non-indigenous ophiuroid Ophiothela mirabilis Verrill, 1867 associated with marine sponges with different morphologies, Biological Invasions 16: 77=-93

Glynn, Peter W. and 7 authors (2021b) Non-native brittle star interactions with native octocoral epizoites: an endemic benthic ctenophore in peril?, Marine Biology 168(142): Published online

Glynn, Peter W; Gillette, Phillip R.; Dettloff, Kyle; Dominguez, Joshua D Martinez, Nicolas; Gross; Julie; Riegl,Bernhard M. (2021a) Experimental evidence of minimal effects on octocoral hosts caused by the introduced ophiuroid Ophiothela mirabilis, Coral Reefs <missing volume>: <missing location>

Hendler, Gordon; Brugneaux, Sophie J. (2013) New records of brittle stars from French Guiana: Ophiactis savignyi and the alien species Ophiothela mirabilis (Echinodermata: Ophiuroidea), Marine Biodiversity Records 6: e113

Kaplan, Eugene H. (1988) A Field Gude to Southeastern and Caribbean Seashores, In: (Eds.) . , Boston. Pp. <missing location>

Ruiz, Gregory M.; Geller, Jonathan (2018) Spatial and temporal analysis of marine invasions in California, Part II: Humboldt Bay, Marina del Re, Port Hueneme, ,and San Francisco Bay, Smithsonian Environmental Research Center & Moss Landing Laboratories, Edgewater MD, Moss Landing CA. Pp. <missing location>

Tavares, M. R.; .Franco, A. C. S. ; . Ventura, C. R. R.; .Santos, L. N. (2021) Geographic distribution of Ophiothela brittle stars (Echinodermata: Ophiuroidea): substrate use plasticity and implications for the silent invasion of O. mirabilis in the Atlantic, Hydrobiologia 848: 2093-2103

2002-2021 Invertebrate Zoology Collections Database. <missing description>

2003-2015 Nonindigenous Aquatic Species Database. Gainesville, FL. http://nas.er.usgs.gov