Tamoya Muller 1859

Genus Tamoya Müller, 1859

Figures 2 A, C–E

Valid species: Tamoya haplonema Müller, 1859; Tamoya ohboya, n. sp., described herein.

Insufficiently known to be considered valid species: Tamoya bursaria (Lesson, 1829 as Bursarius cythereae); Tamoya gargantua (Lesson, 1829); Tamoya haeckeli Southcott, 1967 = Tamoya gargantua.

Other named species: Tamoya prismatica Haeckel, 1880 = Tamoya haplonema (see Mayer 1910); Tamoya quadrumana Müller, 1859 = Chiropsalmus quadrumanus (see Agassiz 1862); Tamoya virulenta Kishinouye, 1910, known in Japan as “Hikurage”, is considered valid, but is a species of Morbakka in the newly erected family Carukiidae (Bentlage et al. 2010).

Diagnosis (following Haeckel 1880): Tamoyidae with deep stomach connected to the subumbrella with 4 prominent perradial mesenteries. Vertical phacellae in the interradii.

Type species: Tamoya haplonema Müller, 1859, by subsequent designation by Haeckel (1880).

Remarks: Müller (1859) erected the genus Tamoya for two cubozoan species from Santa Catarina state (southern Brazil), Tamoya haplonema and Tamoya quadrumana (= Chiropsalmus quadrumanus), which today we recognize as representatives of separate orders. At the time, however, Müller believed that the two were so similar that he could provide just a single description, pointing out the specific differences throughout his manuscript. He distinguished Tamoya from Carybdea Péron & Lesueur, 1810, the only other cubozoan genus described at the time, based on the morphology of the bell margin, stomach extensions, origination of the tentacle bases, presence or absence of a sphincter, whether the gastric cirri pointed towards the stomach or the bell, and whether or not the cirri were hollow. These characters are somewhat nebulous and have been widely disregarded by subsequent workers (e.g., Claus 1878, Haeckel 1880, Maas 1903, Mayer 1910, Kramp 1961, Gershwin & Alderslade 2005). Claus (1878) discussed the generic diagnosis presented by Müller (1859) in detail and considered that the characters invoked either do not differ substantially from those of Carybdea or are uninterpretable, and thus concluded that the designation of a new genus for the specimens from Brazil was not warranted. However, Claus (1878) did not actually inspect the specimens studied by Müller (1859), but simply relied on Müller’s description, which arguably contains several shortcomings regarding erection of the genus Tamoya.

Clearly, Tamoya quadrumana is a chirodropid (a clade of cubozoans not recognized at the time of Müller’s description) and so distinct from any carybdeid that it was soon moved into its own genus, Chiropsalmus, by Agassiz (1862: 174; as Chiropsalmus quadrumanus). Subsequently, Haeckel (1880: 445–446) established the order Chirodropida (family Chirodropidae at the time) to accommodate Chiropsalmus and his new genus Chirodropus. Haeckel (1880: 442–443), in disagreement with Claus (1878), also modified the diagnosis of Tamoya to contain all those species that possess a stomach that protrudes deep into the subumbrellar cavity and is connected to the subumbrella by mesenterial bands (Fig. 2 C & E). Furthermore, the gastric cirri of Tamoya sensu Haeckel (1880) are arranged in four interradial bands running along the stomach walls from the upper portion of the stomach down towards the manubrium (Fig. 2 C, D & E). As Haeckel (1880) pointed out, the stomach of Tamoya differs so strongly from the stomach of Carybdea that taxonomic distinction is warranted. For comparison, the stomach of Carybdea is shallow, the gastric phacellae cluster in the corners of the stomach, and mesenteries are absent (Fig. 2 F). Mayer (1910: 512) considered both Tamoya and Carybdea to be valid, though he posited that the distinction between the two may be based on intergrading characters. Following Haeckel (1880), the genus Tamoya persists, is in widespread use, and is consistent with molecular phylogenetic analyses (Bentlage et al., 2010).