Tubella Carter, 1881

Pinheiro, Ulisses & Nicacio, Gilberto, 2012, Resurrection and redefinition of the genus Tubella (Porifera: Spongillidae) with a worldwide list of valid species, Zootaxa 3269, pp. 65-68 : 65-67

Genus Tubella Carter, 1881

Type species: Tubella paulula Carter, 1881 (by subsequent designation, De Laubenfels, 1936: 37)

Proposed new synonymy. Trochospongilla Vejdowsky, 1883: 31 ; Penney & Racek, 1968: 133 (and synonymy therein).

Uruguaya in part: sensu Hinde, 1888: 10 (part); Weltner, 1895: 130 (part); Cordero, 1924: 117 (part); Gee, 1932: 44 (part); Penney, 1960: 60 (part); Penney & Racek, 1968: 143 (part); Belén, 1968: 285 (part).

Not Uruguaya Carter, 1881: 100 ; Volkmer-Ribeiro & De Rosa-Barbosa, 1978: 505 (and synonymy therein).

Uruguayella Bonetto & Ezcurra de Drago, 1969: 356.

Tubella is defined as a sponge with an encrusting growth form. Consistency fragile to moderately hard. Ectosome with spicules in the dermal membrane. Choanosome anisotropic, pauci- or multispicular fibres, more dense at the sponge base. Variable amount of spongin. Megascleres oxeas, strongyles and tornotes, straight or slightly curved, stout or slender, smooth or spiny. Microscleres absent. Gemmules grouped or singly scattered. Gemmules spherical, enveloped in single or multi-gemmular pneumatic pseudo-cage, armoured by megascleres. Foramen present. Gemmular theca monolayered consisting of compact spongin. Gemmoscleres are birotulates minute, short, smooth, stout or slender shaft radially embedded in gemmules. Rotules equal or unequal diameter, entire, circular, often bent, turned in the same direction, usually the upper rotule cup shaped and smaller than the inner.

Bonetto & Ezcurra de Drago (1969) erected the genus Uruguayella to contain five species from six described earlier belonging to Uruguaya : Uruguayella repens ( Hinde, 1888) ; Uruguayella macandrewi ( Hinde, 1888) ; Uruguayella pygmea ( Hinde, 1888) ; Uruguayella amazonica ( Weltner, 1895) and Uruguayella ringueleti (Bonetto & Ezcurra, 1962) . This proposal was based on these species having birotule gemmoscleres, as opposed to strongyle gemmoscleres in the type species of Uruguaya , Uruguaya coralliodes ( Bowerbank, 1863) . Even considering the very close relationship among these species and Trochospongilla, Bonetto & Ezcurra de Drago (1969) considered that differences like texture of the specimens and conformation of the skeleton justified the creation of Uruguayella . This opinion was ignored by Volkmer-Ribeiro & De Rosa-Barbosa (1978, 1985) who classified the Uruguaya species bearing birotule gemmocleres as Trochospongilla amazonica and T. repens , also synonymizing Uruguaya macandrewi , U. pygmea and U. ringueleti as T. repens . Manconi & Pronzato (2002) complicated this situation when they maintained the validity of the genus Uruguayella with all five species proposed by Bonetto & Ezcurra de Drago (1969), and they did not consider the papers by Volkmer-Ribeiro & De Rosa-Barbosa (1978, 1985). Uruguayella , Trochospongilla and Uruguaya (except Uruguaya corallioides ) possess birotule gemmoscleres and lack microscleres, and on the basis of these features we consider here that these genera as a junior synonyms of Tubella .

We also examined the slide of Meyenia anonyma from the Amazonas River, Brazil deposited in the Natural History Museum London (NHM formerly BMNH), including measurements of the spicules ( Fig. 1 ). Tubella anonyma ( Carter, 1881) was described as a species of Meyenia based only on the description of structures resembling gemmules, which were found over the surface of a leaf. Notwithstanding that it has never had been recollected since first described, the species was mentioned in three occasions in the literature review as Ephydatia anonyma by Weltner (1895), and as Tubella anonyma by Gee (1932) and Penney (1960). Since that time it has not been mentioned. In our assessment of all records of freshwater sponge species from Brazil, we examined Carter’s unique slide in the NHM (probably the type), and noted that the putative gemmule-like structures of T. anonyma were in fact vegetal material ( Fig. 1 a–h). This vegetal structure was described as composed of a membranous coat striated longitudinally supporting a reticulation with a central structure extremely minute, erect and conical with sharp spines ( Fig. 1 d–g). This structure is not homologous with any type of spicule, and Carter (1881) considered it to be a statoblast (gemmoscleres), which was indicative of an undescribed species of Spongilla , and which he stated as being an accidental occurrence on the surface of another species ( Fig. 1 h). We analyzed the slide and found the presence of megascleres and microscleres, which possibly belong to Metania spinata ( Carter, 1881) . Thus, we propose that Tubella anonyma is an invalid species.

Trochospongilla tanganyikae ( Evans, 1899) has been described as a species of Spongilla from Lake Tanganyika. In the original description, Evans described megascleres as strongyles and tornotes, thickly covered with small spines, microcleres as oxeas and its gemmules lack gemmoscleres. Burton (1938) revised Spongilla tanganyikae and described for the first time birotule gemmoscleres, and transferred this species to the genus Trochospongilla . In this work he also examined Metania vesparium (Martens, 1868) , with which T. tanganyikae is associated, and differentiated both species explaining the presence of oxea microscleres in the original description of S. tanganyikae . Penney & Racek (1968) analyzed T. philottiana and questioned the validity of T. tanganyikae on account of its features from records made by Evans (1899), Kirkpatrick (1906) and Burton (1938) from African specimens ( Congo). Penney & Racek (1968) suggested that these records are a typical T. philottiana , which was also reported from India, China and Indonesia. Although these species have similar features, T. tanganyikae was described before T. philottiana , demonstrating the misconception proposed by Penney & Racek (1968). Because these species have disjunct populations, we consider the African specimens of T. philottiana as junior synonym of T. tanganyikae , and Asian specimens should be reviewed.

Volkmer-Ribeiro & De Rosa Barbosa (1985) considered Trochospongilla tenuissima as ecomorphic variation of T. minuta . However, Van Soest (2012) lists T. tenuissima as a valid species. Here, we agree with Volkmer-Ribeiro & De Rosa Barbosa (1985) and propose T. tenuissima as a synomym T. minuta .

From this analysis, Tubella currently has 16 valid species: Tubella amazonica ( Weltner, 1895) ; Tubella delicata (Bonetto & Ezcurra de Drago, 1967); Tubella gregaria ( Bowerbank, 1863) ; Tubella horrida (Weltner, 1893) ; Tubella lanzamirandai (Bonetto & Ezcurra de Drago, 1964); Tubella latouchiana (Annandale, 1907) ; Tubella leidii ( Bowerbank, 1863) ; Tubella minuta (Potts, 1887) ; Tubella paulula ( Bowerbank, 1863) ; Tubella pennsylvanica (Potts, 1882) ; Tubella petrophila (Racek, 1969) ; Tubella philottiana Annandale, 1907 ; Tubella repens ( Hinde, 1888) ; Tubella singpuensis (Cheng, 1991) ; Tubella tanganyikae ( Evans, 1899) and Tubella variabilis (Bonetto & Ezcurra de Drago, 1973).

Figures

FIGURE 1. Meyenia anonyma from Amazonas River, Brazil, deposited in the Natural History Museum London: a) slide. b) Oxea megascleres. c) Oxea microscleres. d – g) Vegetal structures. h) Reproduction of Carter’s (1881) original plate illustrating M. anonyma. Scale bars: b) 150 µm, c) 40 µm, d) 180 µm, e) 170 µm, f) 75 µm, g) 15 µm.