Cupuladria minuta, Almeida & Souza & Vieira, 2021

Almeida, Ana C. S., Souza, Facelucia B. C. & Vieira, Leandro M., 2021, Free-living bryozoans (Cheilostomatida, Cupuladriidae) from northeastern and northern Brazil, Zootaxa 4933 (1), pp. 39-62 : 46-49

Cupuladria minuta n. sp.

( Figs 4 , 5 ; Table 2 )

urn:lsid:zoobank.org:act:3FBC284A-E974-44EF-9748-162904BAE633

Cupuladria canariensis: Marcus & Marcus, 1962: p. 285 , pl. 1, figs 1–3.

Non Cupularia canariensis Busk, 1859: p. 66 , pl. 23, figs 6–9.

? Cupuladria canariensis: Braga, 1967: p. 8 ; Barbosa, 1971: p. 1.

? Cupuladria biporosa: Tommasi et al., 1972: p. 144 .

Cupuladria biporosa: Buge, 1975: p. 443 ; Vieira et al., 2008: p. 15 (in part).

Non Cupuladria biporosa Canu & Bassler, 1923: p. 29 , pl. 47, figs 1, 2.

Material examined. Holotype: UFBA 129.1 , BA (Camaçari), 12º52’ S, 38º12’ W, 45 m, sand, col. 2008 by LAMEB- UFBA, 1 colony . Paratypes: UFBA 129.2 , UFBA 129.3 , UFBA 129.4 , UFPE 537 , BA (Camaçari), same data as holotype, 4 colonies . Additional specimens: UFBA 1424.1 , UFBA 1424.2 , BA (Abrolhos Archipelago), 2 colonies; UFBA 182.2 , UFBA 182.5 , BA (Ilhéus-Porto Seguro), 7 colonies; UFBA 189.1 , UFBA 2842.1 , BA ( Cairu ), 3 colonies ; UFBA 192.1 , UFBA 212.1 , UFBA 2367.2 , UFBA 2584.2 , UFBA 2720.1 , BA ( Maraú ), 7 colonies ; UFBA 168.1 , BA (off Baía de Todos os Santos), 19 colonies ; UFBA 165.1 , UFBA 170.1 , UFBA 197.1 , BA ( Baía de Todos os Santos), 35 colonies ; UFBA 148.2 , UFBA 167.1 , UFBA 183.1 , UFBA 194.1 , UFBA 196.1 , UFBA 858.1 , UFPE 538 , BA ( Salvador), 75 colonies; UFBA 129.5 , UFBA 130.1 , UFBA 131.1 , UFBA 149.1 , UFBA 198.1 , UFBA 199.1 , UFBA 209.2 , UFBA 214.1 , UFBA 218.2 , UFBA 219.1 , UFBA 1738.2 , UFBA 2365.1 , UFPE 539 , BA ( Camaçari ), 94 colonies ; MOUFPE 42.2 - Akaroa 139, SE (Aracaju), 1 colony ; MOUFPE 40.2 - Akaroa 154, SE (Itaporanga d’Ajuda), 2 colonies ; MOUFPE 36.2 - Akaroa 103 , MOUFPE 39.2 - Akaroa 94 , MOUFPE 46.2 - Akaroa 92 , MOUFPE 52.3 - Akaroa 171 , MOUFPE 56.2 - Akaroa 181, AL (Coruripe), 12 colonies ; UFPE 530 , RN ( Guamaré ), 6 colonies ; MOUFPE 07.2 -MA14, MA (Cedral), 1 colony; MOUFPE 27.2 -MA18, MOUFPE 35.1 -MA41, PA (Bragança), 2 colonies; MOUFPE 17.2 -MA34, PA (S„o Jo„o de Pirabas), 1 colony; MOUFPE 02.2 -MA56, MOUFPE 03.2 -MA62, MOUFPE 05.2 -MA60, MOUFPE 22.2 -MA59, MOUFPE 24.2 -MA68, MOUFPE 30.2 -MA64, AP (Macapá), 8 colonies.

Type locality. Camaçari , Bahia State, northeastern Brazil .

Etymology. From Latin, minuta , small, alluding to the small size of the colony.

Diagnosis. Cupuladria with small, flat, discoidal colonies, with central area formed by vicarious avicularia up to the fifth astogenetic generation; autozooids rhombic, lozenge-shaped in frontal outline; vicarious avicularia with auriform opesia and square to rectangular basal sectors, with 1–6 small openings per sector.

Description. Colonies discoidal, flat ( Fig. 4 A–D), 1.3–5.7 mm in diameter (mean 3.7 mm; n = 70; standard deviation 0.9 mm). Central area of colony, up to the fifth astogenetic generation, comprising vicarious avicularia ( Figs 4 A–D; 5A). Autozooids rhombic, nearly lozenge-shaped in frontal outline, with oval opesia occupying about three-quarters of zooidal length ( Fig. 5B ). Cryptocyst granular, more developed distally and laterally than proximally; descending laterally but septula remaining visible. Gymnocyst reduced to a narrow, raised rim more evident laterally and distolaterally. Vicarious avicularia lozenge-shaped, with auriform opesia having proximolateral flaps, occupying less than half of zooidal length; surface of chamber smooth, gymnocystal; cryptocyst smooth around proximal third, granulated around distal two-thirds ( Fig. 5C ). Vibracular chamber subtriangular, located distal to each autozooid and avicularium, with auriform opesia having unilateral proximal flap; frontal calcification smooth, gymnocystal; granulated cryptocyst evident distally ( Fig. 5B, C ). Basal sectors squared to slightly rectangular, with 1–6 small (commonly 1–2) openings per sector ( Fig. 5D ).

Remarks. Cupuladria minuta n. sp. is easily distinguished from other species reported in Brazil because the central area of the colony is composed of vicarious avicularia up to the fifth astogenetic generation. The main differences between C. minuta n. sp. and C. monotrema include the maximum diameter of the colony (up to 5.7 mm in C. minuta n. sp.; up to 12 mm in C. monotrema ), the central area of the colony (formed by vicarious avicularia in C. minuta n. sp.; predominantly by autozooids in C. monotrema ), and the number of openings per basal sector (up to six small openings in C. minuta n. sp.; up to four large openings in C. monotrema ).

Among species of Cupuladria , C. minuta n. sp. most closely resembles C. incognita Herrera-Cubilla, Dick, Sanner & Jackson, 2006 , C. multesima Herrera-Cubilla, Dick, Sanner & Jackson, 2006 , C. planissima HerreraCubilla & Jackson, 2014, C. remota Cook & Chimonides, 1994 and C. veracruxiensis Herrera-Cubilla & Jackson, 2014 , in having the central area of the colony composed of vicarious avicularia. The new species differs from C. incognita , C. multesima and C. planissima in having flat, discoidal colonies with square to rectangular basal sectors with up to six openings per sector (cone-shaped colonies with long-rectangular to irregular basal sectors with up to 16 openings in C. incognita ; dome-shaped colonies with radial basal sectors with up to 18 and 14 openings in C. multesima and C. planissima , respectively) ( Herrera-Cubilla et al. 2006; Herrera-Cubilla & Jackson 2014). Differences between C. minuta n. sp. and C. remota include the colony diameter (up to 5.7 mm in C. minuta n. sp.; up to 12 mm in C. remota ), the number of vicarious avicularia in the central area of the colony (up to the fifth astogenetic generation in C. minuta n. sp.; up to the seventh astogenetic generation in C. remota ), the gymnocystal calcification of the autozooids (developed as a lateral and distolateral raised rim in C. minuta n. sp.; very short in C. remota ), and the number of openings per basal sector (up to six in C. minuta n. sp.; up to two in C. remota ) ( Cook & Chimonides 1994). Finally, C. minuta n. sp. differs from C. veracruxiensis in having no autozooids between the vicarious avicularia of the central area of the colony up to the fifth astogenetic generation (autozooids are seen among vicarious avicularia of the central area of the colony of C. veracruxiensis , as showed in Figs 3.1 and 3.2 of HerreraCubilla & Jackson (2014)), autozooids lozenge-shaped in outline (hexagonal in C. veracruxiensis ), the vibracular chamber and vicarious avicularia with less extensive gymnocyst evident (more extensive in C. veracruxiensis ), and square to rectangular basal sectors (rectangular to irregular in C. veracruxiensis ) ( Herrera-Cubilla & Jackson 2014).

Some specimens of Cupuladria from Brazil were attributed by Marcus & Marcus (1962) to C. canariensis . This and other records of C. canariensis from Brazil ( Waters 1888; Marcus & Marcus 1962; Braga 1967; Barbosa 1971; Tommasi et al. 1972) were later assigned by Buge (1975) and Vieira et al. (2008) to C. biporosa . Both C. canariensis and C. biporosa were originally described based on specimens from the Eastern Atlantic (Africa) ( Busk 1859; Canu & Bassler 1923). Cadée (1975, 1979) and Herrera-Cubilla et al. (2006) have already pointed out that C. canariensis seems absent from the Western Atlantic. Cook & Chimonides (1994) described morphological differences between specimens from the Eastern and Western Atlantic attributed to C. biporosa , indicating that more than one species is involved. Brazilian specimens having the central area of the colony composed mostly of vicarious avicularia ( Braga 1967; Barbosa 1971; Tommasi et al. 1972) were probably initially misassigned to C. canariensis and later attributed to C. biporosa ( Buge 1975; Vieira et al. 2008). Differences between C. minuta n. sp. and C. canariensis include the size of the colony (maximum diameter 5.7 mm in C. minuta n. sp.; 25 mm in C. canariensis ), the vibracula (monomorphic in C. minuta n. sp.; dimorphic in C. canariensis ), and the basal sectors (square to rectangular, with 1–6 small openings per sector in C. minuta n. sp.; long-rectangular, with 4–20 large openings per sector in C. canariensis ) ( Cook & Chimonides 1994). Cupuladria minuta n. sp. differs from C. biporosa in having colonies up to 5.7 mm in diameter (up to 16 mm in C. biporosa ), the central area of the colony composed of vicarious avicularia (autozooids and vicarious avicularia in C. biporosa ), lateral septula visible in frontal view (obscured by the cryptocyst in C. biporosa ), and small basal openings (large in C. biporosa ). The descriptions and figures provided by Marcus & Marcus (1962) and Buge (1975) based on specimens from S„o Paulo, Rio de Janeiro and Amapá suggest that these specimens belonged to C. minuta n. sp. —all have small colonies, the central area of the colony composed of vicarious avicularia, and the basal sectors bearing more than two openings per sector ( Marcus & Marcus 1962; Buge 1975). Other records of C. biporosa from Brazil ( Braga 1967; Barbosa 1971; Tommasi et al. 1972) provide no description and/or figures, and further examination is needed to confirm whether they are C. minuta n. sp. or some other Cupuladria species.

Distribution. Western Atlantic: Brazil (S„o Paulo, Rio de Janeiro, Bahia, Sergipe, Alagoas, Rio Grande do Norte, Maranh„o, Pará and Amapá) ( Marcus & Marcus 1962; Buge 1975; present study).

Figures

FIGURE 3. Cupuladria monotrema (Busk, 1884). A–D. UFBA 007.1. A. Autozooids in the central area of the colony and a vicarious avicularium (arrow). B. Enlargement showing an autozooid and vibracular chambers. C. Vicarious avicularium and its vibracular chamber. D. Colony basal view. Scale bars: A, D. 500 µm; B, C. 100 µm.

FIGURE 4. Cupuladria minuta n. sp. A–D. Frontal view of colonies in different astogenetic stages with central area formed by vicarious avicularia. A. UFBA 129.2, paratype, 2.0 mm in diameter. B. UFBA 129.3, paratype, 2.4 mm in diameter. C. UFBA 129.4, paratype, 3.4 mm in diameter. D. UFBA 129.1, holotype, 4.2 mm in diameter. Scale bars: 1 mm.

FIGURE 5. Cupuladria minuta n. sp. A–D. UFBA 129.1, holotype. A. Vicarious avicularia in the central area of the colony surrounded by autozooids. B. Detail of autozooid and its vibracular chamber. C. Detail of vicarious avicularium and its vibracular chamber. D. Colony basal view. Scale bars: A, D. 500 µm; B, C. 100 µm.