Turritopsis dohrnii

Invasion History

First Non-native Panama (Pacific) Tidal Record: 2007
First Non-native Panama (Caribbean) Tidal Record: 2006

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Panama Invasion History:

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Invasion history elsewhere in the world:

Miglietta and Lessios (2009) surveyed populations of Turritopsis spp. at many locations in the Atlantic and Pacific in 2002-2009. On the Caribbean coast of Panama, medusae of T. dohrnii were found at Galeta Island, near the Panama Canal entrance, this hydrozoan was also found in many samples in Bocas del Toro, about 200 km west of the Canal. On the Pacific side of Panama, medusae of T. dohrnii were found in Panama Bay, and were one of the more abundant hydromedusae present (Miglietta and Lessios 2009). In Japan, polyps of this species were found in 2002 in 'southern Japan' and in 2003 on Okinawa (Miglietta et al. 2006; Miglietta and Lessios 2009).

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Description

Turritopsis dohrnii is a hydrozoan with both a polyp and medusa stage. The hydroid colonies vary from sparingly branched colonies a few mm high to much-branched, multiple-stemmed colonies up to 35 mm high. The hydranths branch off at an acute angle from the hydrocaulus (stem), and then curve away. The stem and branches are covered by a firm perisarc, often encrusted with detritus and algae. The hydranths are spindle-shaped and have 12-20 filiform (thread-like) tentacles, spread over most of their length, and end in a conical hypostome. The pear-shaped medusa buds arise singly on short stems from below the hydranths. The hydranths can be colorless or pinkish.

Newly released medusae have 8-12 tentacles, and a conical manubrium, with four fluorescent-yellow pads between the roots of the interradial canals. The adult medusae are up to 2.7 mm in height and 3.3 mm in diameter, with 14-32 tentacles. Numbers of tentacles in adult medusae vary regionally with: 8 in Bocas del Toro, Panama; 12-24 in Italy; and 14-24 in Japan, probably in part due to environmental influences. The tentacles sometimes have terminal swellings. The manubrium is cross-shaped in cross section, ending in four lips, and reaches to the bell margin. It is red, while the gonads are brownish, with four rust-colored dots, between the radial canals. (Description from: Bouillon et al. 2004; Schuchert 2004)

Medusae of the genus Turritopsis have been widely identified as T. nutricula McCrady, 1857 (described from Charleston, South Carolina) around the world. Turritopsis dohrnii is often treated as a synonym of T. nutricula; however, different populations have been shown to have different morphologies and life histories, both in the medusa and polyp stage (Schuchert 2004). A genetic study of Turritopsis identified seven species from the Atlantic and Pacific, four of which are unnamed (Miglietta et al. 2006). Turritopsis dohrnii, described from the Mediterranean, has a disjunct distribution and genetic similarity indicative of human-mediated introduction (Miglietta and Lessios 2009). Additional cryptic species of Turritopsis may exist, and other 'silent invasions' are possible. Identification of the cryptic species of Turritopsis is only possible by molecular means (Miglietta and Lessios 2009).

Turritopsis dohrnii has been christened 'Immortal Jellyfish' in the popular press, because starved medusae can settle to become an undifferentiated cyst, which grows into a new polyp, restartimg the life cycle. This process of transdifferentiation makes each individual organism potentially immortal (Miglietta et al. 2009).

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Taxonomy

Ecology

General:

The hydrozoan Turritopsis dohrnii forms branched hydroid colonies up to 35 mm high. The colonies grow medusa buds which release planktonic medusae. The medusae have separate sexes, and release gametes which fuse to form planulae, which settle to form hydroids. The hydroid stage of this species can be found attached to rocks, docks, pilings and ships’ hulls. A unique feature of the genus is that starved medusae settle to become an undifferentiated cyst, which can grow into a new polyp. This process of transdifferentiation restarts the life cycle, and makes each individual organism potentially immortal (Miglietta et al. 2009).

Food:

Zooplankton

Trophic Status:

Carnivore

Carn

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Habitats

General Habitat	Rocky	None
General Habitat	Marinas & Docks	None
General Habitat	Vessel Hull	None
General Habitat	Unstructured Bottom	None
Salinity Range	Polyhaline	18-30 PSU
Salinity Range	Euhaline	30-40 PSU
Tidal Range	Subtidal	None
Vertical Habitat	Epibenthic	None
Vertical Habitat	Planktonic	None

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Tolerances and Life History Parameters

Maximum Height (mm)	35	Bouillon et al. 2004; Schuchert 2004
Broad Temperature Range	None	Warm temperate-Tropical
Broad Salinity Range	None	Polyhaline-Euhaline

General Impacts

No impacts have been reported from introduced populations of Turritopsis dohrnii. However, in Panama Bay, Panama this was one of the seven most abundant hydromedusan taxa (Miglietta et al. 2008).

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References

Bouillon, Jean; Medel, Maria Dolores; Pagès, Francesc; Gili, Josep-Maria; Boero, Ferdinando ; Gravili, Cinzia (2004) Fauna of the Mediterranean Hydrozoa., Scientia Marina 68(suppl. 2): 5-438

Kingon, Kelly; Robertson, D. Ross 2019 The alien Damselfish, Neopomacentrus cyanomos at Trinidad. https://zenodo.org/records/3364568



Marquez, Federico M.; Zabala, Soledad; Bokenhans, Verena; Cumplido, Mariano; Espinosa, Free; Bigatti, Gregorio; Averbuj, Andres (2024) Predation of the invasive green crab Carcinus maenas on the edible snail Buccinastrum deforme, targeted as the most important nearshore marine gastropod fishery from Patagonia, Argentina, Regional Studies in Marine Science 69(103299): Published online
https://doi.org/10.1016/j.rsma.2023.103299

Miglietta, M. P.; Piraino, S.; Kubota, S.; Schuchert, P. (2006) Species in the genus Turritopsis (Cnidaria, Hydrozoa): a molecular evaluation., Journal of Zoological Systematics and Evolutionary Research 45: 11-19

Miglietta, Maria Pia; Rossi, Marco; Collin, Rachel (2008) Hydromedusa blooms and upwelling events in the Bay of Panama, Tropical East Pacific., Journal of Plankton Research 30(7): 783-793

Miglietta, Maria Pia; Lessios, Harilaos A. (2009) A silent invasion., Biological Invasions 11: 825-834

Morri, Carla; Puce, Stefania; Bianchi, Carlo Nike; Bitar, Ghazi; Zibrowius, Helmut; Bavestrello, Giorgio (2009) Hydroids (Cnidaria: Hydrozoa) from the Levant Sea (mainly Lebanon), with emphasis on alien species, Journal of the Marine Biological Association of the United Kingdom 81: 49-62

Schuchert, Peter (2004) Revision of the European athecate hydroids and their medusae (Hydrozoa, Cnidaria): Families Oceanidae and Pachycordylidae, Revue Suisse de Zoologie 111(2): 315-369

Spano, Carlos; Rozbaczylo, Nicolás; Häussermann, Vreni; Bravo, Ricardo (2013) Redescription of the sea anemones Anthopleura hermaphroditica and Bunodactis hermafroditica (Cnidaria: Anthozoa: Actiniaria) from Chile, Revista de Biología Marina y Oceanografía 48(3): 521-534
DOI 10.4067/S0718-19572013000300010

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