Turritopsis fascicularis

Miglietta, Maria Pia, 2016, Turritopsis fascicularis Fraser, 1943 (Cnidaria: Hydrozoa): redescription and discussion of its phylogenetic position within the genus, Zootaxa 4097 (3), pp. 426-433 : 428

Re-description of Turritopsis fascicularis

Class Hydrozoa, Subclass Anthoathecata , Order Hydroidolina, Sub Order Filifera, Family Oceaniidae ( Figures 1– 3 ).

Colony erect and shrub like, branched, 7–10 cm tall. General color of the colony ranges from yellow to dark brown. Colony polysiphonic with thick (3-4 mm) ( Fig. 1 ) base and main hydrocauli and hydrocladia composed by several tubes running together and parallel to each other. Thinner hydrocladia branch from main hydrocaulus. Single polyps (rarely two) branch off hydrocaulus and hydrocladia ( Fig. 2 ). Stolons are covered with perisarc. Perisarc stops at the base of each single polyp. Annulations absent. Polyps clavate, on short pedicels with approximately 12-15 scattered tentacles. Hypostome conical, sometimes slightly elongate. Tentacles appear thick. All observed colonies were fertile. Medusa buds on a very short pedicel, arising from the distal portion of the pedicel, and just below hydranth. Fertile polyps observed with only one medusa bud at the time. Medusa buds with 4 radial canals and 4 or 8 short rudimentary tentacles ( Fig. 3 ).

Figures

FIGURE 1. Panoramic of the full colony, polysiphonic branches, and branching patterns (A, B, D, E from colony C 14 - 500; C from colony H 2). Size bar: 1 mm in B, C and D; 500 µm in E.

FIGURE 2. Branching patters of the colony, and multiple views of polyps and tentacle arrangement (all from colony H 2).

FIGURE 3. Medusa buds from (A, C, D, E from colony C 14 - 500; B from colony H 7). Size bar: 500 µm in A, B and E, 1 mm in C, 200 µm in D).