Tedania (Tedania) ignis (Duchassaing & Michelotti, 1864)

(Figs. 17 A–F; 18) (Tab. 7)

Examined material. Sample K5: Hawai’i, O’ahu Island, 1 m, 31 August 2003.

Description. Pulpy sponge, about 1.5 mm thick, massively encrusting a branch of Carijoa riisei, 7 cm long (Fig. 17 A). The anthocodiae are free from the sponge (Fig. 17 A). Surface macroscopically smooth, consistency soft and tough. Beige in ethanol (Fig. 17 A).

Skeleton. The ectosomal skeleton is not clearly observable; it is mainly composed of tylotes and onychaetes protruding from the surface and making it hispid (Fig. 17 B); paucispicular tracts of tylotes are tangentially disposed. The choanosome is an irregular reticulation of uni- or paucispicular tracts of styles. In general the skeleton appears isotropic.

Spicules. Styles frequently curved (Fig. 17 C), 245 – (254 ± 6.9) – 270 x 3.75 – (7.8 ± 2.7) – 10 μm. Tornotes with rounded and microspined points (Fig. 17 D), 187.5 – (199.3 ± 5.8) – 207.5 x 2.5 – (3.9 ± 0.7) – 5 μm. Onychaetes separable in two size classes with numerous intermediate forms. Onychaetes I, finely spined, with symmetrical tips (Fig. 17 E), 160 – (170 ± 10.6) – 180 μm; onychaetes II with clear asymmetrical tips and slightly spread long spines (Fig. 17 F), 40 – (49 ± 8.6) – 60 μm.

Distribution and remarks. St. Thomas, Curaçao, Bonaire, St. Martin, Puerto Rico, Florida (van Soest 1984); Antigua (Carter 1882), Jamaica (Hechtel 1965), Bahamas (de Laubenfels 1949; Wiedenmayer 1977), Bermuda (Ridley & Dendy 1887; de Laubenfels 1950b), Gulf Coast (Little 1963), Belize (Burton 1954 as T. anhelans), Panama (de Laubenfels 1936b), Hawai’i (de Laubenfels 1950a) and Palau (de Laubenfels 1954).

Van Soest, 1984 re-described the paralectotype of Thalysias ignis Duchassaing & Michelotti (1864), and reported the presence of two size classes of onychaetes (about 50 μm and 180 μm in length); the same author also recognized, in his material from Caribbean, two distinct size classes of onychaetes, with numerous intermediate sizes. On the contrary, Hechtel (1965) and Wiedenmayer (1977) detected the presence of a single category only. Bhattacharya analysis based on onychaete lengths shows the presence of two main size classes corresponding to those of Duchassaing & Michelotti (1864) sensu Van Soest (1984: Tab. 7 and Fig. 18). The most frequent class (group 1), 54.6%, comprises onychaetes between 40–60 μm (Tab. 7 and Figs. 17 F; 18); the second class with a wide population of spicules (group 3), 34.5%, comprises onychaetes of about 160–180 μm in length (Tab. 7 and Figs. 17 E; 18). An additional small group (group 2), 10.9%, with a mean of 110 μm is probably composed of growing onychaetes I (Tab. 7 and Fig. 18).

The species has been considered to be present in Hawai’i since 1950 (de Laubenfels 1950a; Kelly-Borges & Valentine 1995), having been transported there along with other sponges of the fouling community (Bergquist 1967). Tedania ignis was also recorded in massive form in O’ahu Island (Kane’ohe Bay, in 2006) and in Pearl Harbor (in 2007) (B.C. pers. observ.).

In the absence of molecular evidence we can not exclude that T. ignis constitutes a species complex, comprising morphologically indistinct species.