Echinocyamus grandiporus Mortensen, 1907

Echinocyamus grandiporus Mortensen, 1907 View in CoL . AphialD: 124270. New record. ( Fig. 2 View FIGURE 2 a-b).

Material examined. Seven preserved specimens with catalogue numbers (stations included): 124270-B39 (B10 V 02); 124270-B40 (B11 V 04); 124270-B41 (B11 V 04).

Description. As for other species of the genus, E. grandiporus has a small test, subcircular in outline, with a flat oral side ( Fig. 2a, b View FIGURE 2 ). On apical disc, ocular pores the same size or larger than genital pores. Madreporite slightly inflated. Genital and ocular plates fused, with four gonopores ( Fig. 2a View FIGURE 2 ). Aborally, petals poorly developed, small and inconspicuous ( Fig. 2a View FIGURE 2 ). On the oral side, peristome margin with slight infundibulum, and more or less pentagonal in outline ( Fig. 2b View FIGURE 2 ).

Distribution. Atlantic Ocean: south and north Azores, west of Portugal, Masachusetts, from south of North Carolina to south of Florida, Gulf of Mexico, Caribbean Sea, Brazil (In front of Sao Luís, Joao Pessoa and Sao Paulo) ( Mortensen, 1907; Mortensen, 1927; Schultz, 2009; Kroh, & Mooi, 2022; OBIS, 2022)

Bathymetric range. 30 m ( USNM E 20468 View Materials )– 2500 m ( OBIS spp-71-416_D3 2009). Present study: 744–1091 m.

Remarks. Sixteen species of the genus Echinocyamus Van Phelsum, 1774 are recorded worldwide. The morphology of Echinocyamus grandiporus is similar to that of Echinocyamus macrostomus Mortensen, 1907 and E. pusillus (O.F. Müller, 1776) . In E. grandiporus , the test outline is rounded, the madreporite is elevated, and petals are poorly developed and shorter than in E. pusillus . In addition, the periproct is closer to the posterior margin of the test compared to E. pusillus . Ocular pores in E. grandiporus are the same size or larger than the gonopores, while ocular pores in E. pusillus are smaller than gonopores. In E. macrostomus , the peristome and the periproct are larger than in E. grandiporus , ocular pores are smaller than gonopores and the periproct is smaller than the peristome, transverse, and positioned near the posterior margin of the test.