Comactinia auxiliadorae, De Souza & Martins & Fukuda & Souto, 2025

De Souza, Tulio H., Martins, Luciana, Fukuda, Marcelo & Souto, Camilla, 2025, A new species of Comatulidae (Echinodermata: Crinoidea) from the southwestern Atlantic coast, Zootaxa 5716 (1), pp. 93-106 : 95

Comactinia auxiliadorae sp. nov.

( Figures 1–5 Table 1–2)

Type material. Holotype. BRAZIL. Rio de Janeiro, Campos Basin : 22°41'76"S, 40°51'32"W, 90 m, coll. R/V Emma McCall , st. J500, 25.i.2010, CD diameter 1.56 mm ( MZUSP 4250 ).

Paratypes. BRAZIL. Rio de Janeiro, Campos Basin : 22°25'S, 40°35'W, 106 m, 1961, 10 specs ( MZUSP 3377 ) ; 22°41'S, 40°51'W, 90 m, 25.i.2010, 8 specs ( MZUSP 3399 ) ; 22°20'S, 40°11'W, 202 m, 25.ii.2010, 2 specs ( MZUSP 3440 ) ; 22°20'S, 40°12'W, 178 m, 25.ii.2010, 3 specs ( MZUSP 3455 ) ; 22°41'S, 40°50'W, 93 m, 25.ii.2010, 4 specs ( ZUEC-CRI 17 ) .

Figures

FIGURE 1. Comactinia auxiliadorae sp. nov. (A, C–E, G–J) paratype (MZUSP 3399) and (B, F) holotype (MZUSP 4250). Ethanol-preserved specimen in (A) oral view and (B) aboral view (red arrow pointing to centrodorsal and white arrow to terminal claw); (C) detail of a detached cirrus; (D) specimen in aboral view showing Ibr1 plates (white arrow) and br1 plates (black arrow) in opposition laterally at the proximal angles; (E) arm with gonads (white arrows); (F) brachials in oblique view [pinnulation only present in br4 and br8, absent in other proximal brachials (white arrows)]. (G–J) SEM photomicrographs of brachials: (G) articular surface of br2; (H) articular surface of br5 [PS absent]; (I) upper view of br2; (J) upper view of br5. Abbreviation: PS—pinnular socket.

FIGURE 2. (A–B) Comactinia auxiliadorae sp. nov. (MZUSP 4250, holotype): (A) proximal brachials in oblique view: proximal (black arrow) and middle (white arrow) pinnulars of oral pinnule (Pa); (B) detail of proximal pinnulars of oral pinnule. (C–D) Comactinia echinoptera (MZUSP 3375): (C) proximal brachials in aboral view: proximal pinnular of oral pinnule (black arrow indicates the carina); (D) detail of proximal pinnulars of oral pinnule. (E–F) Comactinia meridionalis meridionalis (MZUSP 3380): (E) proximal brachials in aboral view: proximal pinnular of oral pinnule (black arrow); (F) detail of proximal pinnulars of oral pinnule.

FIGURE 3. Morphology of comb teeth. (A–B) Comactinia auxiliadorae sp. nov. (MZUSP 4250, holotype), oral view: teeth broadened and flattened (middle teeth; white arrows) or narrow and rounded triangular (proximal and distal teeth; black arrows), separated, confluent with the exterior. (C) Comactinia echinoptera (MZUSP 3399), oral view: teeth rectangular, notched and continuous or closely-apposed (white arrow), confluent with the exterior. (D) Comactinia meridionalis (MZUSP 3380), oblique view: teeth rounded, well-separated (white arrow), nonconfluent. (E–G) Outline of comb teeth of (E) C. echinoptera, (F) C. meridionalis and (G) C. auxiliadorae sp. nov.

FIGURE 4. SEM images of main characters of Comactinia auxiliadorae sp. nov. (MZUSP 3399, paratype). (A–C) Centrodorsal in: (A) aboral, (B) adoral, and (C) lateral views. (D–F) Radial in: (D) aboral and (E) oral views; (F) articular face to Ibr1. (G–J) Ibr1: (G) proximal, and (H) distal articular face; (I–J) detail of stereom deposition pattern of distal articular face to Ibr2. (K–M) Ibr2 in: (K) proximal articular face; (L) in upper view; (M) distal articular face. Abbreviations: pa—polar area; sk—cirrus socket; br—basal rays (incision); cc—central cavity; iaf—interarticular ligament fossa; mf—muscle fossa; rnc—radial nerve canal; tr—transverse ridge; lf—ligament fossa; amb—position of ambulacrum; nc—nerve canal; fr—fulcral ridge; ac—axial canal; alf—aboral ligament fossa; lp—ligament pit.

FIGURE 5. SEM images of main characters of Comactinia auxiliadorae sp. nov. (MZUSP 3399, paratype). (A–C) br1 in: (A) proximal and (B) distal articular face; (C) in upper view. (D–F) br2: (D) proximal and (E) distal articular face; (F) detail of pinular socket. (G–I) br3: (G) proximal and (H) distal articular face; (I) detail of stereom deposition pattern of syzygy articulation. (J–L) br4: (J) proximal and (K) distal articular face; (L) in upper view. Abbreviations: iaf—interarticular ligament fossa; mf—muscle fossa; lf—ligament fossa; fr—fulcral ridge; ac—axial canal; amb—position of ambulacrum; ps—pinnular socket; cr—crenula; cu—culmen.