Rhabdopleura recondita Beli, Cameron & Piraino, 2018

Gordon, Dennis P., Randolph Quek, Z. B. & Huang, Danwei, 2024, Four new species and a ribosomal phylogeny of Rhabdopleura (Hemichordata: Graptolithina) from New Zealand, with a review and key to all described extant taxa, Zootaxa 5424 (3), pp. 323-357 : 338

Rhabdopleura recondita Beli, Cameron & Piraino in Beli et al., 2018 ( Fig. 5C )

Type locality. Near Tricase Port , Lecce, Italy, 39.8829° N, 18.4055° E, ~ 70 m depth, occurring within zooidal and other cavities of host bryozoans .

Key features. Inception of ringed erect tubes is direct. The creeping portion of the colony is non-tubular, comprising smooth-walled expansions lacking zigzag sutures, within bryozoan zooids; the free pectocaulus is not adherent to the inner-wall of the creeping tube. Septa separating individual zooids were not found. Colonies extend only a few millimetres. Erect tubes with fusellar collars project up to 0.67 mm from bryozoan orifices and holes in dead bryozoan zooids. Fusellus height is 37±11 μm.

Comment. Like R. compacta , colonies of R. recondita are highly distinctive, as well as substratum-limited, and unlikely to be confused with any other species.

Figures

FIGURE 5. Original illustrations of three described species of Rhabdopleura characterized by direct-frontal inception of ringed erect tubes (A‒C). Erect-tube inception in R. compacta (D‒F) appears to be a form of indirect erect-tube inception. Note that the direction of zooid budding is the same in A to C. A, Rhabdopleura mirabilis (from Sars 1872, pl. 1, fig. 5). B, Rhabdopleura annulata (from Norman 1921, fig. 4). C, Rhabdopleura recondita (after Beli et al. 2018, fig. 2C). D‒F, Rhabdopleura compacta (respectively after Hincks 1880, pl. 72, fig. 8; Stebbing 1970b, fig. 1; Stebbing 1970a, fig. 3).