Elpidium purium, Pereira & Rocha & Martens & Pinto, 2023

Pereira, Julia S., Rocha, Carlos E. F., Martens, Koen & Pinto, Ricardo L., 2023, Six new species of Elpidium Müller, 1880 (Podocopida: Limnocytheridae) from Eastern Brazil, Zootaxa 5258 (1), pp. 1-38 : 30-35

Elpidium purium n. sp.

Figs. 20–23

urn:lsid:zoobank.org:act:F364686F-90B3-4F5C-A4D7-A257F03253FF

Diagnosis. Carapace medium-sized (length of male = 844 µm; length of female = 868 µm) and elongated (width/ length ratio = 0.8; height/length ratio = 0.5). Surface brownish with sparse setae and normal pore canals. Left valve overlapping right one. Strong sexual dimorphism: posterior contour in dorsal and ventral views acuminated in males, truncate in females. Ventral surface flat in central region. In dorsal and ventral views, carapace slightly asymmetric. In right lateral view, external flange subtle, dorsal margin arched, ventral margin nearly straight. Hinge bar long (slightly longer than 2/3 of length of dorsal margin); anterior and posterior proto-tooth with similar development. Cop without differentiation of distal glans and ejaculatory duct, short, U-shaped. Lower ramus long, finger-type. Distal lobes slightly asymmetric, short (basis width/distal lobe length ratio = 0.5), with straight apex and no digital expansion.

Etymology. The name is a reference to the ethnic group Puri, one of the indigenous people that inhabited stretches of the Brazilian littoral, including the municipality of Domingos Martins, State of Espírito Santo, where the species was found. In the indigenous language, the term Puri originally meant bold, brave, courageous.

Type Material. Holotype: a dissected male ( MZUSP 40319 ) with valves dried and coated for scanning electron microscopy stored in a micropaleontological slide and appendages mounted in a sealed slide with glycerin.

Allotype: a dissected female ( MZUSP 40320 ) stored like the holotype.

Paratypes: two males ( MZUSP 40312 , MZUSP 40310 ) and a female ( MZUSP 40311 ) dissected and stored like the holotype ; three males ( MZUSP 40313 , MZUSP 40314 , MZUSP 40315 ) and three females ( MZUSP 40316 , MZUSP 40317 , MZUSP 40318 ) dried and coated for scanning electron microscopy stored in micropaleontological slides; males (~9) and females (~22) ( MZUSP 40321 ) kept whole in a vial with 70% ethanol .

Type Locality. Tank-bromeliads from Domingos Martins, Espírito Santo, Brazil. Approximated geographic coordinates: 20º24′55.2″ S, 40º51′45.7″ W. Material collected on Nov. 11, 2006, by Carlos E. F. Rocha .

Description of the male.

Measurements. L: 844 µm; W: 652 µm; H: 460 µm.

Carapace ( Fig. 20A–I ). Medium-sized (L = 844µm). Surface with sparse setae and normal pore canals. Subtle ornamentation. In dorsal and ventral views, posterior contour acuminate. Carapace slightly asymmetric in posterior contour and greatest width. In dorsal view ( Figs. 20A–C ), anterior end slightly acuminate. In ventral view ( Figs. 20D–F ), surface flat on central portion. In right lateral view ( Figs. 20G–I ), carapace elongated, left valve overlapping right one from antero-dorsal to posterior margins; dorsal margin arched; postero-ventral margin angular, anterior margin slightly pointed, with small external flange.

Left valve ( Fig. 20J–L ). In internal view with flange present on anterior, ventral and posterior margins, discontinued by bow funnel-shaped structure. Selvage well marked on anterior and posterior regions, weakly marked on ventral region. Bow funnel-shaped structure narrow. Calcified inner lamella and vestibule broader in anterior than in posterior region.

Right valve ( Fig. 20M ). In internal view with flange broad in anterior, narrow on ventral and posterior regions, discontinued by bow funnel-shaped. Selvage well marked from anterior to posterior proto-tooth, forming narrow bow funnel-shaped structure on oral region. Calcified inner lamellae and vestibules broader in anterior region than in posterior one. Hinge bar long (slightly longer than 2/3 of dorsal margin length), thin, with posterior and anterior proto-teeth of similar development.

Hemipenis ( Fig. 22D ). With broad, rounded and sclerotized muscular body. Main appendage elements: copulatory complex (cop plus LR) and DL; cop without differentiation of distal glans and ejaculatory duct, short, U-shaped. LR long, finger-type. DL slightly asymmetric, short (basis width/distal lobe length ratio = 0.5), with straight apex and no digital expansion; ds thin, with length similar to DL length; fl with a pair of setae and numerous pseudochaetae.

Other appendages as in Elpidium oxumae n. sp. ( Figs. 21A, B, D–G , 22A–C ).

Description of female.

Measurements. L: 868 µm; W: 732 µm; H: 496 µm.

Carapace ( Fig. 23A–I ). Medium-sized (L = 868 µm) with strong sexual dimorphism: females with major width displaced posteriorly due to brooding chamber and posterior contour truncate. In dorsal and ventral views, carapace asymmetric in posterior contour. In right lateral view, left valve overlapping right from antero-dorsal to posterior margins; dorsal margin arched; ventral margin nearly straight.

Antenna ( Fig. 21C ). Similar to equivalent in males, but terminal segment with vestigial seta, hyaline formation and three biserrate claws instead of two biserrate and one pectinate claws.

Abdomen ( Fig. 22E ). Female end of body rounded and large with spine-like seta, genital lobes and furcal lobes. Spine-like seta stiff, in dorso-medial position; gl rounded, rigid with trabeculae internally; fl rounded but not rigid, with three equal-length pappose setae and numerous pseudochaetae.

Other appendages as in Elpidium oxumae n. sp. ( Figs. 21A, D–G , 22A–C ).

Differential diagnosis. Elpidium purium n. sp. males resemble E. littlei , E. heberti and E. wolfi in the morphology of the posterior part of the carapace. However, instead of the rounded posterior contour observed in females of E. littlei or the acuminated one seen in E. heberti and E. wolfi , E. purium n. sp. females exhibit truncate posterior contours, as in E. bromeliarum . Another carapace difference of this species is the asymmetry: while males are symmetric, females present valve asymmetry, a trait absent in E. littlei , E. wolfi or E. bromeliarum and present only subtly in E. heberti . The U-shaped cop is unique for the present new species. The DL resembles that observed in E. bromeliarum . However, in E. purium n. sp. the right and left DL are asymmetric (although only slightly), which is not observed in E. bromeliarum .

Distribution. The species is currently known solely from tank-bromeliads in the type locality.

Figures

FIGURE 20. Elpidium purium n. sp., male, carapace. A—dorsal view (paratype, MZUSP 40315); B—dorsal view, anterior region detail (paratype, MZUSP 40315); C—dorsal view, posterior region detail (paratype, MZUSP 40315); D—ventral view (paratype, MZUSP 40313); E—ventral view, anterior region detail (paratype, MZUSP 40313); F—ventral view, posterior region (paratype, MZUSP 40313); G—right lateral view (paratype, MZUSP 40314); H—right lateral view, anterior region (paratype, MZUSP 40314); I—right lateral view, posterior region (paratype, MZUSP 40314); J—left valve, internal view (paratype, MZUSP 40310); K—left valve, anterior region (paratype, MZUSP 40310); L—left valve, posterior region (paratype, MZUSP 40310); M—right valve, internal view (paratype, MZUSP 40310). Scale bars: A, D, G, J, M—200 µm; B, C, E, F, H, I, K, L—100 µm.

FIGURE 21. Elpidium purium n. sp., A, B, D–G male, C, female, appendages. A—antennula (holotype, MZUSP 40319); B— antenna (holotype, MZUSP 40319); C—antenna (allotype, MZUSP 40320); D—mandible, coxa (holotype, MZUSP 40319); E—mandible, palp (holotype, MZUSP 40319); F—maxillula, palp (holotype, MZUSP 40319); G—maxillula, respiratory plate (exopodite) (holotype, MZUSP 40319). Scale bars: A–C—0.05 mm, D–G—0.01 mm.

FIGURE 22. Elpidium purium n. sp.,A–D, male, E, female, appendages.A—first thoracic limb (holotype, MZUSP 40319); B— second thoracic limb (holotype, MZUSP 40319); C—third thoracic limb (holotype, MZUSP 40319); D—hemipenis (holotype, MZUSP 40319); E—abdomen (allotype, MZUSP 40320). Scale bars: A–E—0.05 mm.

FIGURE 23. Elpidium purium n. sp., female, carapace. A—dorsal view (paratype, MZUSP 40318); B—dorsal view, anterior region (paratype, MZUSP 40318); C.—dorsal view, posterior region (paratype, MZUSP 40318); D—ventral view (paratype, MZUSP 40316); E—ventral view, anterior region (paratype, MZUSP 40316); F—ventral view, posterior region (paratype, MZUSP 40316); G—right lateral view (paratype, MZUSP 40317); H—right lateral view, anterior region (paratype, MZUSP 40317); I—right lateral view, posterior region (paratype, MZUSP 40317); J—right valve, internal view (paratype, MZUSP 40311); K—right valve, internal view, anterior region (paratype, MZUSP 40311); L—right valve, internal view, posterior region (paratype, MZUSP 40311); M—left valve, internal view (paratype, MZUSP 40311); N—left valve, internal view, anterior region (paratype, MZUSP 40311); O—left valve, internal view, posterior region (paratype, MZUSP 40311). Scale bars:A, D, G, J, M—200 µm; B, C, E, F, H, I, K, L, N, O—100 µm.