Baseodiscus maculosus, (BÜRGER, 1895A)

Kajihara, Hiroshi, Abukawa, Shushi & Chernyshev, Alexei V., 2022, Exploring the basal topology of the heteronemertean tree of life: establishment of a new family, along with turbotaxonomy of Valenciniidae (Nemertea: Pilidiophora: Heteronemertea), Zoological Journal of the Linnean Society 196, pp. 503-548 : 532

publication ID	https://doi.org/ 10.1093/zoolinnean/zlac015
publication LSID	lsid:zoobank.org:pub:78C56409-FCCF-4116-8D8C-FF66B247C56C
DOI	https://doi.org/10.5281/zenodo.7036941
persistent identifier	https://treatment.plazi.org/id/038A8132-EE76-ED5B-FF56-CF09FB4EFEC8
treatment provided by	Plazi
scientific name	Baseodiscus maculosus
status

Treatment

BASEODISCUS AFF. MACULOSUS ( BÜRGER, 1895 A) View in CoL View at ENA

( FIG. 3B View Figure 3 )

Baseodiscus cf. delineatus: Chernyshev, 2016: 290 View in CoL (in part) (Cù Lao Re Island, Vietnam).

? Eupolia maculosa Bürger, 1895a: 604 View in CoL ; Bürger, 1895b: 28, pl. 2, fig. 2 (Pohnpei, Caroline Islands, Micronesia).

? Baseodiscus maculosus: Bürger, 1904: 84 ; Gibson, 1995: 304, 368.

? Baseodiscus delineatus var. curtus: Coe, 1940: 261 (in part).

Material examined: One specimen (DNA voucher ICHUM 6324 View Materials ), 23 May 2007, among dead corals, 2–4 m depth, Cù Lao Re Island (15°23′N, 109°05′E), Vietnam, collected by A. V. Chernyshev GoogleMaps .

Sequences: From ICHUM 6324 View Materials : LC178674 View Materials , 16S (482 bp); LC190950 View Materials , COI (658 bp) .

Description: Body 3–4 cm long. Background body colour pale yellow, mottled over entirety with numerous minute brown dots ( Fig. 3B View Figure 3 ); dots sparser ventrally. Head with numerous eyes and two transverse cephalic furrows, each with secondary grooves.

Distribution: Baseodiscus maculosus s.s. is known only from the original description from Pohnpei (formerly, Ponape), Caroline Islands, Micronesia ( Bürger, 1895b); our specimen identified as Baseodiscus aff. maculosus was from Vietnam.

Remarks: Our specimen was collected from Cù Lao Re Island, Vietnam, 5400 km distant from the type locality. We tentatively identify it as B. aff. maculosus on the basis of the similarity in body markings, consisting of minute, dark-coloured dots spread all over the pale-coloured body. However, the dots in the Vietnam specimen are denser than indicated in the original illustration ( Bürger, 1895b, pl. 2, fig. 2) and its body (3–4 cm) was much shorter than Bürger (1895a, b) indicated for the type specimen (c. 50 cm long, 6 mm wide). The specimen from Vietnam may thus represent a different species. Johnson & Johnson (2019b) photographed an individual from the Marshal Islands (labelled ‘ Emplectonema ? sp. 1’) that was more than 1 m long, with sparser spots and appears much more similar to B. maculosus . Coe (1940) wrote that part of the material he identified as B. delineatus var. curtus differed from B. delineatus in having ‘markings composed of small red or brown dots’, suggesting that the former taxon might include B. maculosus . Baseodiscus aff. maculosus seems to feed on terebellid polychaetes (see Potential food items below).