Neonesidea dinochelata ( Kornicker, 1961 )

Maddocks, Rosalie F., 2021, Taxonomic applications of the esophageal flapper valve in the Genus Neonesidea (Bairdioidea, Podocopida, Ostracoda), including descriptions of new and poorly known species from the Caribbean and Gulf of Mexico, Zootaxa 4903 (4), pp. 451-492 : 458-464

Neonesidea dinochelata ( Kornicker, 1961)

( Figure 5 A–U, Graphs 1, 2)

1961 Bairdia dinochelata sp nov: Kornicker, p. 65, Pl. 1, figs. 4a–d, Text-figs. 8I–O.

1969 Neonesidea dinochelata (Kornicker) .—Maddocks, p. 33, Figs. 12 f–m.

partim 1983 Neonesidea dinochelata (Kornicker) .—Palacios-Fest et al., Table 1, Pl. 1, fig. 8 (only) [fig. 9 is N. sp. aff. N. dinochelata ].

? 1989 Neonesidea dinochelata (Kornicker) .—Bold, Table 2.

Non 1974 Neonesidea dinochelata (Kornicker) .— Maddocks 1974, p. 208, Pl. 2, figs. 1–3 [= N. florea n. sp.].

Material. Eighteen subfossil specimens.

GRAPH 1. H/L scatter plot for adult and juvenile LV and RV of N. dinochelata , N. florea , and N. sp. aff. dinochelata . There is no overlap between the populations of N. dinochelata and N. florea , but N. sp. aff. dinochelata is intermediate in size and proportions and overlaps with both.

GRAPH 2. H/L scatter plot for adult LV and RV of N. dinochelata from five localities: the Bahama Islands, Guantanamo Bay ( Cuba), Belize, Grand Cayman Island, and the Florida Keys. As usual, LV are slightly higher than RV. Known females plot in the upper right of the cluster, and known males plot in the lower left.

Dimensions: Specimen 4047W from UH 2371, Bahamas: LVL 0.779 mm, LVH 0.459 mm, RVL 0.804 mm, RVH 0.429 mm. Kornicker reported the following dimensions for the holotype female specimen 500-1: L 0.84 mm, H 0.51 mm. He reported the dimensions of a complete carapace as L 0.78 mm, T 0.46 mm, H 0.48 mm. Maddocks (1969) reported the following dimensions: adult male USNM 121277 , LVL 0.82 mm, LVH 0.44 mm, RVL 0.72 mm, RVH 0.39 mm; adult female USNM 121278 , LVL 0.78 mm, LVH 0.47 mm, RVL 0.79 mm, RVH 0.44 mm. It appears that females are longer than males and proportionally higher, with more rounded, high-arched dorsal margins. See also Graphs 1–2 .

Remarks: Partial descriptions of the soft parts by Kornicker (1961) and Maddocks (1969) did not include the esophageal valve or the male antenna. More investigation of the soft anatomy is needed in order to distinguish N. dinochelata consistently from similar species.

The carapace is smooth, high-arched dorsally, inflated ventromedially, and somewhat flattened ventrally but not extremely so. Fresh specimens are brown in color, darkest in a vertical streak at mid-length, with clear margins and anterodorsal eye region. The AMS has a nearly horizontal alignment of four thin scars. Kornicker reported that the anterior and posterior margins of the LV are denticulate, but no denticles have been observed in the specimens available. A few LV have a minute spinule or tubercle exactly at the posteroventral angle, accompanied by one or two marginal granules, which are not visible in external lateral view. These granules have little taxonomic value, because some other species of Neonesidea display granular micro-ornament.

Distribution: N. dinochelata was originally described from Bimini Island, in the northern part of the Great Bahama Bank, by Kornicker (1961). Additional specimens from Kornicker’s samples were described by Maddocks (1969). It was subsequently reported from Cozumel Island and the Caribbean coast of Mexico ( Palacios-Fest et al. 1983, Machain-Castillo & Gío-Argáez 1993), although one of the illustrations ( Palacios-Fest et al. 1983, fig. 9) may represent a different species (N. sp. aff. N. dinochelata ). Its range was extended to Belize and Nicaragua by Bold (1989, on the basis of an unpublished M.S. thesis by Manning 1985). It is not mentioned in faunal lists for the southern Gulf of Mexico (the reefs off Vera Cruz, the Bay of Campeche, the West Coast of Yucatan, and Alacran Reef on the northern Yucatan platform; by Krutak 1982, Bold 1989, table 1, Machain-Castillo et al. 1990, Machain-Castillo & Gío-Argáez 1990, 1992). The population reported under this name by Maddocks (1974) from the Flower Garden Banks of Texas is actually N. florea n. sp.

In this study N. dinochelata was identified in dry sediment samples collected from the Little Bahama Bank, the Florida Keys, Belize, Cuba, and Grand Cayman Island. It does not occur in Bermuda or the Flower Gardens.

Figures

FIGURE 5. A–U, Neonesidea dinochelata (Kornicker). A, C, specimen 4071RV; B, D, specimen 4070LV; E–F, specimen 4047W; G–H, specimen 4048RV; I, J, specimen 4068RV; J, L, specimen 4067LV; all from the Bahamas. M, specimen 4949RV; N–O, specimen 4050LV; both from Belize. P–T, specimen 4065W from Grand Cayman Island. U, specimen 4069RV from Florida Keys. V–Z, Neonesidea sp. aff. N. dinochelata (Kornicker). V, specimen 4052RV from Belize; W–Z, specimen 4072W from Guantanamo Bay, Cuba. A, E, G, I, M, P, U–V, W, all RV exteriors in TL; B, F, J, N, Q, X, all LV exteriors in TL; C, H, K, R, Y, all AMS of RV; D, L, O, S, Z, all AMS of LV; T, DV of RV and LV in TL. Scale bar = 50 µm.

FIGURE 12. Neonesidea longisetosa (Brady). A–O, subfossil specimen 4045M from Belize; P–Q, specimen 1652M from the Bahamas; S, subfossil specimen 4053W from Jamaica. A. A–D, hemipenis, with distal details; E, corner tooth of plate; F–G, VV of plate at high and low focus; H, interior of posteroventral region of RV, showing dry fragments of plate and ring; I–L, diagonal view of plate standing upright within RV interior, from high focus to low focus; M–N, edge view of posterior margin of same plate after removal from valve, showing pyramidal teeth and row of ventral setules, the dorsal surface is up (concave); P–R, hemipenis, with distal details; S, VV of EV with ring and plate. Scale bar = 50 µm.