Bairdoppilata diatreta, Maddocks, 2025

Maddocks, Rosalie F., 2025, “ By any other name ”: The saga of Bairdia bradyi van den Bold, 1957 in the Caribbean and Gulf of Mexico, with eight new species of Bairdoppilata (Ostracoda, Podocopida), Zootaxa 5628 (1), pp. 1-78 : 28

Bairdoppilata diatreta sp. nov.

(Graphs 1, 6; Figures 2C–D ; 3A–D ; 4C–F, I–J, L ; 5A–D, L–M ; 6A–J ; 21O–Q ; 32Y–Z ; 33 AA–BB)

1974 Bairdoppilata sp. —Maddocks, p. 209 (part; not Pl. 2, figs. 4–7, 18 = Ba. floreana ).

Derivation of Name: from the Latin adjective diatretus, -a, -um; pierced with holes, filigreed, carved, embossed; to describe the patch pattern.

Material Examined: 20 specimens.

Types: Holotype specimen 4158 LV, USNM 1751246 ; Paratype specimen 4157 RV, USNM 1751248 ; illustrated specimens USNM 1751248–1751253 .

Type Locality: Florida, UH 1294, Biscayne Bay, off Virginia Key , opposite marine station, water depth 1 m, January 1958. 25 o 44’N, 80 o 09’W .

Occurrence: Florida (Biscayne Bay only), East and West Flower Gardens, and Gyre station 7.

Dimensions: Holotype specimen 4163 LV, L 0.881 mm, H 0.546 mm . Paratype specimen 4162 RV, L 0.871 mm, H 0.484 mm . Paratype specimen 4156Car, L 0.914 mm, W 0.425 mm. See also Graph 1.

Diagnosis: Carapace of moderate length, relatively high, diamond-shaped in dorsal outline; surface densely punctate; opaque patch pattern filigreed with narrow streaks.

Description: Carapace narrowly domed, nearly symmetrical; greatest height near mid-length, moderate dorsal overreach, nearly straight anterodorsal and posterodorsal slopes, level ventral margin; blunt caudal process, slightly swollen but not ridged; no swelling at anterior angle ( Figures 3B–D ; 5A ). Dorsal outline only slightly inflated, diamond-shaped, thickest just anterior to mid-length, with straight anterolateral and posterolateral margins tapering symmetrically to narrow ends ( Figure 5L–M ). Surface densely punctate.

Opaque patch pattern filigreed, consisting of swirls and lobes surrounding circular transparent fields, approximately symmetrical in LV and RV ( Figures 2C–D ; 3A–D ). Central opaque patch inverted triangular with rounded edges, with lobate anterodorsal and higher posterodorsal extensions. Irregular, sigmoid stripe connects central spot to dark dorsal surface. Anterior and posterior opaque spots circular, not ventrally extended. Separate marginal opaque spots at mid-anteroventral, mid-ventral, and mid-posteroventral locations. Smaller, lobate spots and curved streaks occupy anterolateral and posterolateral fields, variable in shape but sharply contrasting with transparent regions; in effect, as if large transparent circles had been cut out of formerly continuous opaque regions.

Hinge with well-developed ligamental striation; supplemental dentition sharply executed ( Figure 6E–J ). ZC broad, vestibules very narrow; selvages straight to weakly curved, nodular zones of flange narrow to moderately wide ( Figures 3D ; 6A–B ). Aligned pores of RPC visible within gape in ventral view ( Figure 5M ). LV and RV anteroventral and posteroventral margins smooth or with remnants of frill; ( Figures 3C–D ; 6C ).

Juvenile A–1 RV anteroventral margin smooth, posteroventral margin with uneven frill; with dense punctation and opaque patch pattern similar to adult ( Figure 4C–F ).

Remarks: Ba. diatreta is similar to Ba. collaevata , but smaller, with more conspicuous punctation, and the opaque patch pattern is more delicate.

In Graph 1, the LV cluster is offset (up and to the right) relative to the RV cluster (down and to the left), by the usual magnitude for bairdiids. The RV cluster overlaps with the RV cluster for Ba. collaevata , but there is no overlap of the LV clusters. LV from the Flower Gardens and the Gyre station are distinctly higher, relative to length, than those from Florida. At any one locality, it is likely that the larger individuals are females, but it is difficult to assess sexual dimorphism because of the small number of specimens ( Table 1).

Maddocks (1974) reported Bairdoppilata sp. from the Flower Gardens, but four species were included in the material: Ba. collaevata , Ba. diatreta , Ba, fithianae , and Ba. floreana . The illustrations are of Ba. floreana . The statement that the species is living in Bermuda applies only to Ba. fithianae .

Figures

FIGURE 2. Surface texture of eight Caribbean species of Bairdoppilata: A–B, Bairdoppilata collaevata sp. nov.; C–D, Bairdoppilata diatreta sp. nov.; E–F, Bairdoppilata fimbriata sp. nov.; G–H, Bairdoppilata fithianae sp. nov.; I–J, Bairdoppilata floreana sp. nov.; K, Bairdoppilata hypsiliformis sp. nov.; L–M, Bairdoppilata sima sp. nov.; N–O, Bairdoppilata thyreoides sp. nov. All exterior views in transmitted light. All scale bars = 100 µm. A–O, surface texture of valves, showing puncta, muri, NPC, opaque patch patterns, AMS, occasional setae, predation scars, and boreholes.

FIGURE 3. A–D, Bairdoppilata diatreta sp. nov.; E–S, Bairdoppilata collaevata sp. nov. All exterior views in transmitted light.All scale bars = 100 µm. A–I, lateral views of RV and LV; J–S, anterior and posterior marginal details of RV and LV: J–K, straight selvage and wide nodular zone; L–M, RPC and remnants of narrow marginal frill–like edging; N–O, LV anterior locules of supplemental dentition; Q–S, scalloped appearance of valve edge.

FIGURE 4. A–B, G–H, K, Bairdoppilata collaevata sp. nov.; C–F, I–J, L, Bairdoppilata diatreta sp. nov. All exterior views in transmitted light. All scale bars = 100 µm. A–B, RV and LV of juvenile instar A–1, with punctation and opaque patch patterns; C–D, RV of juvenile instar A–2, E–F, marginal details of RV of instar A–2, with infold and poorly developed marginal edging; G–L, punctate texture of adult valves, showing puncta, muri, honeycomb structure, AMS, NPC, opaque patch patterns, and boreholes. Surface punctation continues uninterrupted across opaque regions and muscle scars, because they are on lower levels within the valve wall.

FIGURE 5. A–D, L–M, Bairdoppilata diatreta sp. nov.; E–K, N–P, Bairdoppilata collaevata sp. nov. All exterior views in reflected light; B–C, I, immersed in glycerine. All scale bars = 100 µm. A, J, right–lateral views of intact carapaces; B–I, K, lateral views of RV and LV; L, N, dorsal views; M, O–P, ventral views.

FIGURE 6. A–J, Bairdoppilata diatreta sp. nov.; K–Z, Bairdoppilata collaevata sp. nov. A–Q, interior views; R–Z, exterior views. All in reflected light. All scale bars = 100 µm. A–C, M–O, interiors of LV and RV; D–E, hinge of LV and RV, showing ligamental striation; F–H, K–L, P, anterior and posterior supplemental denticles of RV; G–H, selvage and narrow flange of RV; I–J, Q, supplementary locules beneath dorsal overhang of LV; R–S, caudal process, marginal punctation, and spinose posteroventral marginal edging of RV; T–W, delicately punctate marginal bands at anterior and posterior ends, with illusory ruffling or undulation; X–Y, nearly smooth, leather–like, transparent surface, focused on tiny puncta; opaque patch and AMS are lower and out of focus; Z, coarsely punctate surface, covering opaque patch (white) and AMS (dark) below.

FIGURE 21. A–N, Bairdoppilata floreana sp. nov.; O–Q, Bairdoppilata diatreta sp. nov. A–D, J–Q, exterior views; E–I, interior views. A–B, in transmitted light; C–D, G–I, in reflected light; E–F, reflected light in immersion; J–Q, by SEM. All scale bars = 100 µm. A–B, lateral views of RV and LV; C–D, dorsal and right–lateral views of carapace; E, F, raised AMS with moats, central opaque spot (smooth gray), honeycomb structure, and tiny NPC; G, hinge of LV showing ligamental striation; H, entire dorsal edge of RV, showing supplemental dentition and hinge with ligamental striation; I, enlargement of middle part of bar of RV hinge, to show ligamental striation; J–L, lateral views of carapace with setae; M–N, punctate surface, NPC with narrow walls, and simple setae; O–P, lateral views of abraded valves, with slightly swollen anterior end and caudal process; Q, puncta and NPC with narrow walls.

FIGURE 32. At a glance: Right valves of eight new species of Bairdoppilata from the Caribbean and Gulf of Mexico. Each species has a distinctive outline and opaque patch pattern. All in transmitted light. All scale bars = 100 µm.

FIGURE 33. At a glance: Left valves of eight new species of Bairdoppilata from the Caribbean and Gulf of Mexico. Each species has a distinctive outline and opaque patch pattern. All in transmitted light. All scale bars = 100 µm.