Characodoma protrusum ( Thornely, 1905 )

Martha, Silviu O. & Scholz, Joachim, 2025, Shallow-water bryozoans collected during R. V. Meteor expedition 5 / 2 “ MINDIK ” from the Bab-el-Mandeb Strait and Gulf of Aden, along the coasts of Djibouti and Yemen, Zootaxa 5689 (2), pp. 201-243 : 225-226

publication ID

https://doi.org/10.11646/zootaxa.5689.2.1

publication LSID

lsid:zoobank.org:pub:BAB0DE16-2C2B-4503-A528-66D20AAC12E0

persistent identifier

https://treatment.plazi.org/id/753087BE-1553-FFC6-6AFB-FD572A8FFE4A

treatment provided by

Plazi

scientific name

Characodoma protrusum ( Thornely, 1905 )
status

 

Characodoma protrusum ( Thornely, 1905) View in CoL

( Fig. 16.1–6 View FIGURE 16 )

Gemellipora protrusa Thornely, 1905: 119 , fig. 7; Waters 1913: 506, pl. LXX, figs 4–6. Cleidochasma protrusum : partim Harmer 1957: 1040 (part), text-fig. 112, pl. LXXI, figs 2, 4, non pl. LXXI, figs 1, 3 (=

Characodoma suluense ( Soule, Soule & Chaney, 1991)) View in CoL ; Hayward & Cook 1979: 89; Soule et al. 1991: 468, pl. 1, fig. 1,

pl. 2, figs 1, 2;? d’Hondt & Mascarell 2010b: 320. Characodoma protrusum View in CoL : Cook & Bock 1996: figs 12, 13.

Material examined. SMF 11545 About SMF ( 3 specimens; St. 230 KD1; Fig. 16.3 View FIGURE 16 ) , SMF 40792 About SMF (St. 283 KU; Fig. 16.2, 16.4–6 View FIGURE 16 ) , SMF 40806 About SMF (St. 283 KU; Fig. 16.1 View FIGURE 16 ) .

Description. Colony base encrusting, multiserial, unilamellar ( Fig. 16.1 View FIGURE 16 ); colonies becoming rigidly erect, multiserial, bilamellar, dichotomously branching ( Fig. 16.2 View FIGURE 16 ); transition from encrusting to erect growth not observed. Zooids arranged quincuncially, separated by broad and distinct furrows. Pore chambers not observed. Ancestrula and early astogeny not observed.

Autozooids irregularly polygonal to subhexagonal ( Fig. 16.3 View FIGURE 16 ), 298–482 μm (ẋ = 381 ± 48 µm; CV = 13; N = 45 on 3 specimens) long by 221–385 μm (ẋ = 293 ± 42 µm; CV = 14; N = 45 on 3 specimens) wide. Frontal shield slightly convex, finely tuberculate, irregularly pierced by c. 20 circular (areolar) pores at the margins and proximally ( Fig. 16.4 View FIGURE 16 ). Orifice terminal, keyhole-shaped; anter subcircular, 84–123 μm (ẋ = 100 ± 8 µm; CV = 8; N = 45 on 3 specimens) long by 81–100 μm (ẋ = 89 ± 5 µm; CV = 6; N = 45 on 3 specimens) wide, separated by proximomedially directed condyles from the poster; poster trifoliate, with paired, variably developed indentations proximal to the condyles, well-rounded proximally, 33–52 μm (ẋ = 41 ± 4 µm; CV = 10; N = 45 on 3 specimens) long by 26–47 μm (ẋ = 34 ± 4 µm; CV = 13; N = 45 on 3 specimens) wide ( Fig. 16.5 View FIGURE 16 ). Spine bases not observed. Ovicells hyperstomial, globular, 105–150 μm (ẋ = 132 ± 13 µm; CV = 10; N = 45 on 3 specimens) long by 140–203 μm (ẋ = 172 ± 13 µm; CV = 7; N = 45 on 3 specimens) wide, acleithral; ectooecia finely tuberculate, evenly pierced by circular pseudopores ( Fig. 16.4 View FIGURE 16 ) .

Avicularia monomorphic ( Fig. 16.5–6 View FIGURE 16 ), adventitious, usually single, proximolateral to the orifice, second avicularium (if present) distolateral to the orifice, bilaterally symmetrical, dextral or sinistral, kite-shaped, 90–159 μm (ẋ = 122 ± 14 µm; CV = 11; N = 45 on 3 specimens) long by 75–124 μm (ẋ = 96 ± 10 µm; CV = 11; N = 45 on 3 specimens) wide. Avicularian aperture longitudinally elliptical, 54–99 μm (ẋ = 78 ± 10 µm; CV = 13; N = 45 on 3 specimens) long by 38–78 μm (ẋ = 60 ± 7 µm; CV = 12; N = 45 on 3 specimens) wide; crossbar complete, at about half the avicularian length. Rostrum rounded, slightly elevated, proximally directed .

Kenozooids not observed.

Remarks. Characodoma protrusum ( Thornely, 1905) was revised by Soule et al. (1991), who also provided images of the type material. The specimens from the Gulf of Aden closely resemble both this material and additional colonies imaged by Cook & Bock (1996) from Wasini Island, Kenya. However, in the Aden specimens, the trifoliate shape of the poster varies, with indentations proximal to the condyles being inconsistently pronounced and sometimes partially obscured ( Fig. 16.3 View FIGURE 16 ). Despite these minor differences, the Aden specimens are clearly conspecific with Characodoma protrusum , extending the species’ known range into the northwestern Indian Ocean.

Characodoma protrusum has been reported from multiple regions of the Indian Ocean and was also described from the Marquesas Islands, French Polynesia, by d’Hondt & Mascarell (2010b). However, as no images of the Pacific material were provided, its conspecificity with the Indian Ocean populations remains uncertain. Soule et al. (1991) excluded specimens from the Sulu Sea (North Ubian Island, Philippines) from Characodoma protrusum , and instead described Characodoma suluense , which differs primarily in its kidney-shaped poster lacking indentations, and a frontal shield with fewer areolae. Characodoma biavicularium ( Canu & Bassler, 1929) from the Sibuyan Sea near Romblon, Philippines, is distinguished by the presence of a second, smaller, proximally positioned avicularium, and both avicularia types in this species are elliptical.

KU

Biodiversity Institute, University of Kansas

CV

Municipal Museum of Chungking

Kingdom

Animalia

Phylum

Bryozoa

Class

Gymnolaemata

Order

Cheilostomatida

Family

Cleidochasmatidae

Genus

Characodoma

Loc

Characodoma protrusum ( Thornely, 1905 )

Martha, Silviu O. & Scholz, Joachim 2025
2025
Loc

Characodoma suluense

Soule, J. D. & Soule, D. F. & Chaney, H. W. 1991: 468
Hayward, P. J. & Cook, P. L. 1979: 89
1979
Loc

Gemellipora protrusa

Harmer, S. F. 1957: 1040
Waters, A. W. 1913: 506
Thornely, L. R. 1905: 119
1905
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