Bairdoppilata labiata
LV and RV subtriangular, smoothly rounded, equilateral in female, fairly inaequilateral in male, not caudate in lateral view. Males tend to be not as long, and not as high as females. Valve surface of adults smooth. Valves of adults and juveniles covered by many conspicuous sensilla of variable length, from very short to very long; long sensilla barbed. Normal pore canals simple, with narrow rims or without rim. Anterior fringes and posterior marginal denticles well developed. Marginal pore canals long and straight, not very numerous. Calcified inner lamella medium-sized. Hinge anterior and posterior elements with or without very faint denticulation, medial bar finely striate. Carapace subhexagonal, very inflated in dorsal view, with rounded contour, maximum width at mid-length. Eight adductor muscle scars present.
Antennula with several very long setae. Antenna with elongated podomere IV and V; exopodite with 1 very long and 2 short setae; podomere VI with 1 medium-sized anterodistal claw (its length about ¾ that of posterodistal claw), 1 long posterodistal claw, 2 small setae, and 1 medium-sized, fused seta in males; females present a more robust fused seta (claw-like). Masticatory process of Mandibula with several setae, and 1 simple, plus 5 trifurcate, plus 1 bifurcate teeth; exopodite with 1 very long and 2 long setae; podomere IV palp with 1 robust, feathered, distal claw. Vibratory plate of maxillula with 6 subequal strahlen and 25 feathered setae; endites with modified, broad, feathered, distal claws, and also simple setae and claws. Vibratory plate of Fifth limb with 4 proximally segregated strahlen, and 13 feathered setae. Furca with 7 setae; seta 1 (more distal one) thick, seta 2 the longest and distally feathered; seta 4 also long, other setae short, but not vestigial. Brush-shaped organ assymetrical. Genital lobe oval, with very long and tightly coiled internal tube and an external elongated process. Male copulatory limb with subrectangular basal element, followed by a medial subhemispherical element and terminated by an elongated, irregularly shaped distal element, the last terminates in a finger-like process; copulatory tube very elongate and strongly sclerotized; an elongated, flattened process arises from the distal part of the medial element.
LV and RV subtriangular, smoothly rounded, equilateral in female, fairly inaequilateral in male, not caudate in lateral view. Valve surface of adults and juveniles smooth. Hinge anterior and posterior elements without visible teeth. Carapace subhexagonal, very inflated medially in dorsal view. Podomere VI of antenna with 1 medium-sized anterodistal claw, 1 long posterodistal claw, 2 small setae, and 1 medium-sized, fused seta. Furca with 7 setae; setae 2 and 4 longest. Genital lobe oval, with very long and tightly coiled internal tube, and an external elongated process. Male copulatory limb with subrectangular basal element, subhemispherical medial element, and elongated distal element, the last one terminates in a finger-like process; copulatory tube very elongate and strongly sclerotized; an elongated, flattened process arises from the distal part of medial element.
Bairdoppilata simplex (Brady, 1880) also from the Southern Ocean. Maddocks (1969) considered Bairdoppilata labiata a junior synonym of Bairdoppilata simplex, but Brandão (2008) showed that both species are distinct.
Lectotype, LV, L 1.52mm (with spines and fringe) 1.50mm (without spines and fringe), H 0.93mm RV, L 1.61mm (with spines and fringe) 1.53mm (without spines and fringe), H 0.87mm.
Paralectotypes, LV, A L 1.64–1.83mm, H 0.94–1.10mm; (A-1) L 1.32–1.39mm, H 0.80–0.84mm; (A-2) L 1.00–1.08mm, H 0.62–0.68mm; (A-3) L 0.80mm, H 0.50mm; (A-4) L 0.60-0.64mm, H 0.38–0.40mm; (A-5) L 0.49mm, H 0.30mm.
In the report on Ostracoda from the German South Polar Expedition, Müller (1908) described Nesidea labiata from the Gausstation (Indic Sector of the Southern Ocean, 385m depth) (see Fig. 1.18 herein). After studying the subfossil lectotype of Bairdoppilata simplex, and based on Müller’s published illustrations (1908, Pl. 14.1–5), Maddocks (1969: 77) considered N. labiata to be a junior synonym of B. simplex. On the contrary, after Brandão (2008) studied the type material of Bairdoppilata simplex and N. labiata, she consider the second species as valid. The transference of N. labiata to the genus Bairdoppilata, as suggested by Maddocks (1969), is here considered dubious, since the diagnostic “4–6 tiny denticles on ends of right valve ridge articulating with sockets beneath left valve overlap” are not present in the types of N. labiata. No true hinge denticulation was observed in specimens of the Gausstation, in a few cases some kind of undulating structure was observed, but it was more likely due to an irregular relief on the hinge elements than to real teeth. Otherwise, the anterodistal seta of podomere VI of the antenna II is enlarged, clawlike, which is a diagnostic character of Bairdoppilata. For this reason, the assignment to the genus was considered dubious—?B. labiata (Müller, 1908). The differences observed between the lectotype of B. simplex and types of ?B. labiata are described below.
(1) The most conspicuous features that differentiate B. simplex from ?B. labiata are the more arcuate dorsal margin and more broadly rounded posterior margin of the latter species. These differences are not due to sexual dimorphism since both sexes from N. labiata present these characteristics.
(2) Also conspicuous is the difference in dorsal view: ?B. labiata presents very inflated, subhexagonal shape, while B. simplex is more elongate, less wide (Brady, 1880, Fig.b, c).
(3) The hinge denticulation of B. simplex is conspicuous even under an optic microscope, while in ?B. labiata it is very faint, if not absent, even under electron microscopic magnifications.
(4) RV in both species present tri-segmented dorsal margin, but in B. simplex it is more rounded, with inconspicuous posterodorsal angle.
The juvenile LV recorded by Neale (1967, Fig. 2) from the Halley Bay, Antarctic Peninsula, presents a more broadly rounded posterior margin. Consequently this record is herein considered dubious.
Dingle’s (2000) illustrated RV (identified as B. simplex), from the Quaternary of Victoria Land Basin, Antarctica, is similar to the lectotype of B. simplex, but could also be co-specific to ?B. labiata or other bairdioid species.
For the soft part anatomy, I follow Horne et al., 2002 (Horne DJ, Cohen A, Martens K. 2002. Taxonomy, morphology and biology of Quaternary and living Ostracoda. In: Holmes JA, Chivas AR, editors. The Ostracoda. Applications in Quaternary Research. Washington, DC: American Geophysical Union. p 5-35.).
We use the following terms for the limbs/furca from anterior to posterior with alternative names in parenthesis:
antennula (antenna I, Aa, AI, first antenna)antenna (antenna II, AII, Au, second antenna)mandibula (mandible, Md)Maxillula (first maxilla, maxilla I, maxillule, MxI, Mxu)Fifth limb (ApV, Appendage V, first thoracic leg, maxilla, maxilla I, MxI, Mxu, maxilliped, clasper (for males), P1, second maxilla, walking leg)Sixth limb (ApVI, Appendage VI, first thoracic leg, second thoracic leg, P2, walking leg)Seventh limb (ApVII, Appendage VII, cleaning limb, P3, second thoracic leg, third thoracic leg, walking leg)Male copulatory limb (eighth limb, hemipenis, uropod). Whether the Male copulatory limb is homologous to a crustacean limb remains controvertial.Furca (caudal rami, Fu, furcal rami, uropods). The homology of the podocopan furca (anterior to the anus) to a myodocopan furca (posterior to the anus) remains controversial. Similarly, the homology of the ostracod furca to the furca of other crustaceans remains controvertial.
Antennula 1(0/0), 2(.1/0), 3(.1/0), 4(.1/.1), 5(.2/.2), 6(.2/.2.), 7(0/0:3). Antenna 1(0/0:2i), 2(.1/0:1i), 3(0/.3.2), 4(0/.2), 5(.1.2./.1,1), 6[male:(0/0:1c,1c,1,1fs); female:(0/ 0:1c,1c,2,1fc)]. Mandibula palp 1(0/.1.:1i), 2(.2/.2:1i), 3(.4./.1:2i), 4(.1./3pc,2). Maxillula of palp (.3./1:1,1pc). Fifth limb 1(.1 .2. 2-3. 1/0), 2(.2/0), 3(.1/0), 4(0/0:1r,1c). Sixth and seventh limbs 1(.1.1.1.1/0), Exopodite(0/0:2), 2(2/0), 3(.1/0), 4(.1/0), 5(0/0:1r,1c). Furca (0/0:3.4).
Chaetotaxy formula follows Schornikov and Keyser (2004, The morphology and classification of Paradoxostomatinae (Ostracoda) from the nearshore zone of Madeira and the Canary Islands. Revista Española de Micropaleontologia 36: 57-81.) : "Figures without parentheses = podomeres numbered from proximal to distal; + = junction of podomeres. Figures within parentheses = number of setae: numerator = setae on dorsal margin; denominator = setae on ventral margin; integer figures = lateral, medial or apical armature elements, from dorsal to ventral. Figures within parentheses without indexes = normally development setae; r = rudimentary; c = claw-shaped seta or claws; s = sensory seta; p = plumose seta or ray; re = reflexed seta or ray; a = atriumwards ray; t = tooth or tooth-shaped seta; l or m = lateral or medial seta. A dot indicates the presence of an interval between setae or between podomere ends; a colon indicates apical, lateral or medial setae; hyphen indicates variable elements. Commas are used for the sake of clarity e.g. to separate symbols by unarmed podomeres or setae without indexes."
(see an example of the chaetotaxy formula in the figure "EXAMPLE CHAETOTAXY" in this species page)
Previously the syntype series used by Müller to describe “Nesidea labiata” were in a glass containing alcohol and labelled “Nesidea labiata G. W. Müller, Gaus Station (177a), 385m, Deut. Südpolar Exp., 1901–1903, ZMB 13069”. Inside of this larger glass there were six small vials labeled “177a-1.03”, “177a-2.03”, “177a-4.02”, “177a-6.02”, “177a-10.02a”, and “177a-12.02” (see below). These labels most probably indicate the date of collection of each sample, since Müller (1908) stated that these samples were collected between March 1902 and February 1903, and that N. labiata was especially abundant in December. The vial labelled “177a-12.02” is the one with the largest number of specimens. Finally, three more glass slides with valves and dissected soft parts also form part of Müller’s syntype series.
Lectotype (designated by Brandão, 2008): 1 dissected A M (SNB 0683), soft parts on glass slides with permanent medium “Hydromatrix” and 2 valves on a micropaleontological slide, ZMB 13069. Previously this specimen was in a vial containing alcohol and labelled “Nesidea labiata G. W. Müller, Gaus Station (177a.12.02), 385m, Deut. Südpolar Exp., 1901– 1903, ZMB 13069”. A newly dissected specimen was chosen as the lectotype, since the three slides containing the specimens dissected and illustrated by Müller (1908) can not be observed under the higher magnification objective (100X) of an optical microscope because of the large quantity of preserving medium. Furthermore, the valves of these 3 specimens were also preserved in permanent medium (which contain cracks) on glass slide, being impossible to study them accurately.
Paralectotypes: 58 *live specimens preserved in alcohol, 7 RV, 11 LV on micropaleontological slides. All these specimens were in six small vials (see below) and three slides:
*Part of the material listed below as live A, (A-1), (A-2), (A-3), (A-4), (A-5) might or might not contain soft parts, since all the valves from the Gausstation were opaque, it was not possible to be sure if some specimens were live or subfossil.
1) Vial labelled “177a-4.02”—subfossil: 2 A RV, 1 (A-4) RV, 1 A LV, 1 (A-1) LV.
2) Vial labelled “177a-6.02”—*live: 1 A F, 1 (A-1); subfossil: 1 A RV, 1 A LV.
3) Vial labelled “177a-10.02a”—*live: 4 (A-1), 1 (A-4) (one of them dissected SNB 0686).
4) Vial labelled “177a-12.02”—*live: 9 A F (one of them dissected SNB 0682), 9 A M, 5 (A-1) F (one of
them dissected SNB 0685), 6 (A-2), 1 (A-3), 9 (A-4), 1 (A-5) ; subfossil: 1 A RV, 1 (A-2) RV, 4 A LV, 3 (A-1)
LV, 1 (A-2) LV.
5) Vial labelled “177a-1.03”—*live: 1 A, 4 (A-1), 1 (A-4); subfossil: 1 (A-4) RV.
6) Vial labelled “177a-2.03”—*live: 1 (A-2), 1 (A-4).
7) 1 glass slide with permanent medium containing appendages and 2 valves of 1 A M, and labelled
“Nesidea labiata, 1672, Gauss., 177a-12.02, 1 adult male”.
8) 1 glass slide with permanent medium containing appendages and 2 valves of 1 A M, and labelled
“Nesidea labiata, 1674, Gauss., 177a-12.02, 1 adult male”.
9) 1 glass slide with permanent medium containing appendages and 2 valves of 1 A F, plus one closed carapace
positioned in dorsal view, and labelled “Nesidea labiata, 1680, Gauss., 177a-12.02, 1 adult female”.
A, adult; (A-1), (A-2), (A-3), juvenile instars; F, female; H, Height; L, length; LV, left valve; M, male; RV, right valve; SNB, specimen number as catalogued by the Brandão, S. N. (throught this number, it is possible to assign correctly the valves of a single specimen kept in a micropaleontological slide to their dissected appendages in a glass slide); V, valve; ZMH, Zoologisches Institut und Museum, University of Hamburg (Germany); ZMH K-, abbreviation of the Crustacea collection of the Zoologisches Institut und Museum, University of Hamburg (Germany); #, station number.
1908 Nesidea labiata Müller: 99, Fig. 1.a–d.
1967 ?non Nesidea labiata, Neale: 5, 6.
1997 in part Bairdoppilata (Bairdoppilata) simplex, Hartmann: 47, Fig. 11.a–c, e–g.
2000 ?non Bairdoppilata cf. B. simplex, Dingle: 486.
2008 ?Bairdoppilata labiata (Müller, 1908): 384-387, Figs. Figs. 3.18, 4, 5.A–D, I–K, 6, 7, 8.A, C, F, G, J, M–O, R, T, 9.A–F.
Known only from the type locality, Southern Ocean (Indic Sector), 385m.
Brandão, S. N., 2008. New species of Bairdioidea (Crustacea, Ostracoda) from the Southern Ocean and discussions on Bairdoppilata simplex (Brady, 1880), ?Bairdoppilata labiata (Müller, 1908) and Bythopussella aculeata (Müller, 1908). Zootaxa, 1866: 373–452,
(this publication can be freely downloaded from http://www.mapress.com/zootaxa/2008/f/zt01866p452.pdf)