Elpidium wolfi, Pereira & Rocha & Pinto, 2019

Pereira, Julia S., Rocha, Carlos E. F. & Pinto, Ricardo L., 2019, On three new species of Elpidium Müller, 1880 and the re-description of Elpidium laesslei (Tressler, 1956) from Jamaica (Ostracoda: Podocopida: Limnocytheridae), Zootaxa 4604 (1), pp. 103-140 : 122-138

Elpidium wolfi n. sp.

( Figs. 14–19 )

urn:lsid:zoobank.org:act:CEBAF818-2158-4CD5-9BCB-A46108F5AA44

2014 Elpidium sp.3—Danielopol et al.:89, 90, 111, 121, figure 26

Diagnosis. Carapace surface brownish with sparse setae, normal pore canals and subtle ornamentation consisting in foveolae arranged in groups. Sexual dimorphism in carapace present but subtle: posterior end acuminated in both males and females. In dorsal and ventral views, carapace elongated (length/width c 1.3) and asymmetric. In right lateral view, dorsal margin slightly arched, ventral margin straight and flange absent. Distal lobe of hemipenis symmetric, acuminated (length superior to width) with no digital expansion and bearing tiny dorsal seta. Lower ramus short with apex lancet-shaped. Copulatory process wrapped in fold of muscular body and consisting in separated ejaculatory duct and distal glans but not so easily distinguishable. Ejaculatory duct extremely tiny and sinuous. Distal glans S-shaped greatly larger than ejaculatory duct. Distal glans curves connected by thin membrane.

Type material. Holotype: a dissected male ( MZUSP 37397 ) with valves dried and coated for scanning electron microscopy and stored in a micropaleontological slide and appendages mounted on a permanent slide with CMC- 9AF mounting medium . Paratypes: a male ( MZUSP 37398 ) and a female ( MZUSP 37400 ) dissected and stored like the holotype; a male ( MZUSP 37402 ) dried and coated for scanning electron microscopy and stored in a micropaleontological slide; two females ( MZUSP 37399 , MZUSP 37401 ) dissected with appendages mounted on a permanent slide with CMC-9AF mounting medium; five males and 15 females kept whole in a vial with 70% ethanol ( MZUSP 37403 ) .

Type locality. Tank-bromeliad, east of Reach Falls, Portland, Jamaica. Approximate geographical coordinates 18°01'N, 76°18'W. Material provided by Prof. Dr. Wilhelm Foissner (University of Salzburg, Austria) in 2008, without specifying the sampling date .

Derivation of name. We dedicate this new species to Dr.rer.nat.habil. Klaus W. Wolf, Electron Microscopy Unit at the University of the West Indies, Kingston, Jamaica, who facilitated collection on the island.

Description of male. Carapace ( Fig. 14 A–D, I). Medium-sized carapace (length= 0.76 mm). Surface brownish and smooth, with thin and sparse setae; greatest width at mid-length. In lateral view, greatest height at mid-length, ventral margin straight and dorsal margin arched; anterior and posterior regions rounded and similarly wide; ventral surface flat. Valves asymmetric, with left valve overlapping right one on all margins; anteroventral furrow between two valves when carapace is closed.

Left valve ( Fig. 15A, D, E ). In internal view, anterior and posterior margins rounded, dorsal margin arched and ventral margin straight. Inner lamella reduced, being slightly wider in anterior than in posterior region. Vestibule small. Selvage well-marked along valve border and protruded into hinge dorsally. Flange more developed anteriorly than posteriorly; row of pseudochaetae along posterior inner margin.

Right valve ( Fig. 15B, C , F–I). In internal view, anterior and posterior margins rounded, dorsal margin arched and ventral margin straight. Inner lamella relatively small, slightly wider anteriorly. Vestibule small. Selvage wellmarked along valve margin, originating hinge cardinal bar dorsally. Flange small, being larger anteriorly; row of pseudochaetae along posterior inner margin. Central muscle scars four stacked spots. Hinge a long bar on dorsal margin of right valve, ending in a proto-tooth at each end, smaller at anterior and larger at posterior end. Bar slightly crenulated. Left valve with complementary structures.

Antennula ( Fig. 16A , 17A ). Five-segmented. First segment relatively long, with sub-apical expansion bearing tuft of tiny pseudochaetae. Second segment the longest, with single plumose seta in ventro-apical position reaching fourth segment. Third segment small, almost square-shaped, with unique serrate seta in dorso-apical position reaching fourth segment at about mid-length. Fourth segment bigger in length than in width and partially subdivided slightly before mid-length, with two serrate dorso-apical setae about equally long, serrate ventro-apical seta and apically very long serrate ventral seta and three serrate dorsal setae: two short and one long with length equivalent to that of ventro-apical one. Fifth segment (terminal) with three serrate and thin setae, one long and two short and equal in length, plus aesthetasc (Ya), with chemosensorial section representing about 19% of total length of this structure. Third, fourth and fifth segments with a row of pseudochaetae each, covering whole or part of their apical portions. All setae with constrictions.

Antenna ( Fig. 17B ). Protopodite with two segments: ring-shaped coxa and long and arched basis, dorsally with two rows of pseudochaetae and group of pseudochaetae in triangular shape. Endopodite with three segments; first one relatively short with very long serrate seta in ventro-apical position, basis wrapped by expansion of segment and apex reaching second segment apical portion; second segment ventrally with group of pseudochaetae in triangular shape and dorsally three separated groups of long psedochaetae, each group reaching the next one. Second segment long, with length greater than width, bearing two dorso-apical setae, one half as long as the other, serrate seta and aesthetasc (Y) with chemosensorial section representing 10% of total aesthetasc length, in ventro-medial position and apically, two setae: one long, strong and serrated and one tiny. Third segment (terminal) with three equally long claws, two serrate and one pectinate with very strong row of denticles, besides tiny seta and hyaline formation. Exopodite arched and very long, with short seta.

Mandible ( Fig. 16G (represented by female specimen), 17E–G). Coxa bearing eight strong teeth, spoon-shaped modified X1 seta, long plumose seta, two interdental setae (X2 and X3), three interdental spines, and sub-apical plumose seta on inner surface. Palp divided in four segments: basis and three-articulated endopodite; basis with two setae in subapical position and respiratory plate (the exopodite) bearing three long setae and short reflexed seta, all with tiny setules; first endopodial segment bearing two apical setae, one half as long as the other; second endopodial segment with four apical setae, two long and two short; third endopodial segment (terminal) with three setae, two thin and equivalent in length and one larger and longer than other two.

Maxillula ( Fig. 16H, I , 17H ). Composed of three endites, first one with three slender setae equal in length; second and third endites with two spatulate claws and three smooth and slender setae each. Palp with about four rows of tiny pseudochaetae medially-positioned, and two long plumose setae equal in length plus very short vestigial seta on its apical portion. Respiratory plate (exopodite) well developed with several tiny spines on its body and 16 rays plus one reflexed seta, each with several tiny setules.

First thoracic limb ( Fig. 18A , 19B, C ). Basis long and slightly arched, filled with several rows of tiny pseudochaetae; dorsal margin with medium-sized plumose seta plus two short apical pappose setae with basal portion wrapped by expansion of segment. Exopodite a long and plumose seta. Endopodial portion divided in three segments with length greater than width. First one the longest, with several long pseudochaetae in both sides and single and strong biserrate seta, slightly shorter than second segment; second segment with no seta and third segment (terminal) with strong and arched claw, slightly biserrate on its end and bearing tiny vestigial seta and row of tiny pseudochaetae on its basis. Endopodial segments with rows of tiny pseudochaetae in apical and lateral portions.

Second thoracic limb ( Fig. 18C ). Similar to first thoracic limb, being just larger and showing minute ornamentation as follows: basis bearing plumose seta at apex incompletely wrapped by expansion of segment; biserrate seta on first and second endopodial segments equal in length. Third segment (terminal) with strong apical claw slightly longer and more arched than the claw present on first thoracic limb terminal segment.

Third thoracic limb ( Fig. 18B , 19D ). Basis bearing three setae: two slender setae on dorsal margin, one in medial and one, pappose, in apical position, plus plumose exopodial seta on ventral margin in medio-proximal position. All three endopodial segments with length greater than width and total length greater than in two previous thoracic limbs. First segment with single biserrate seta equal in length to second segment and a little slenderer than its homologous structure in first and second thoracic limbs; second segment with transverse row of pseudochaetae on its lateral portion, a structure absent on first and second thoracic limbs, and no setae; third segment (terminal) bearing very long and thin claw with minute vestigial seta on its basis. Terminal claw biserrate as in first and second thoracic limbs, but in approximately 2/3 of its length, not only on its end. All three endopodial segments with rows of tiny pseudochaetae in their apical and lateral portions, longer than those of the two previous thoracic limbs.

Hemipenis ( Fig. 18D, E , 19E, F ). Large, greatly sclerotized and rounded body filled with three main muscle bundles responsible for moving different parts of the hemipenis. Copulatory complex formed by copulatory process and lower ramus medially placed on appendage. Copulatory process long and with constant width from its basis to its apex. Separated ejaculatory duct and distal glans, but distinctively from previous species, ejaculatory duct very small and sinuous, not easy to visualize. The distal glans otherwise greatly evident and with unique S-shape. Distal glans curves connected and kept together by thin membrane. Whole structure wrapped in fold of muscular body that covers about half of total copulatory process length. Lower ramus similar to that found in Elpidium heberti n. sp., being relatively short and not so slender, but distinctively, with apex much more lancet-shaped than rounded. Distal lobe with length greater than width, but with broad basis; apex acuminate but not as much as in Elpidium heberti n. sp. and displaced towards internal side of appendage. Distal lobe internal side greatly concave while external side slightly convex; ventral side with short and slender dorsal seta. Furcal lobe with two pairs of short setae filled with numerous pseudochaetae.

Additional description of female. Carapace ( Fig. 14 E–H). Medium-sized carapace (length= 0.77 mm). In dorsal and ventral views, greatest width at mid-length. In lateral view, greatest height at mid-length, ventral margin straight and dorsal margin arched; anterior and posterior regions rounded and equivalent in width; ventral surface flat. Valves asymmetric, with left valve overlapping right one on all margins.. Posterior region larger than anterior due to the existence of brooding chamber, as opposed to males which have anterior and posterior regions with equivalent widths. Valve asymmetry especially evident in females in ventral view.

Antenna ( Fig. 16 B–F, 17C, D). Very similar to homologous appendage in males, but with tiny seta, hyaline formation and three biserrate claws with approximately equal lengths instead of two biserrate claws and one pectinate claw as in males.

Abdomen ( Fig. 18F ). Female end of body rounded and comprising three main structures: spine-like seta, female genital lobes and furcal lobes. Abdominal spine-like seta very stiff and placed dorso-medially; female genital lobe rounded, rough and with trabeculae internally; furcal lobe also rounded but not rigid, covered with numerous pseudochaetae and bearing two closely inserted setae and a third one placed more anteriorly.

Comparison with other Elpidium species. Elpidium wolfi n. sp. is most similar to Elpidium heberti n. sp. considering external morphology. Both species have low sexual dimorphism on the carapace: males and females with posterior end of the carapace acuminate in dorsal view. However, Elpidium wolfi n. sp. has a unique morphology on its copulatory process. Although it has distal glans and ejaculatory duct separated as for the other species described here, in this case the ejaculatory duct is very small and not as easily visible as in E. littlei n. sp., E. heberti n. sp. and E. laesslei , while the distal glans is large and S-shaped. Besides, the distal glans curves are united by a thin membrane, a characteristic also unique.

Elpidium laesslei ( Tressler, 1956)

( Figs. 20–25 )

Diagnosis. Carapace brownish with sparse setae, normal pore canals and strong ornamentation, composed of individual deep concavities. Sexual dimorphism greatly evident: posterior end of carapace slightly acuminate in males and rounded to truncate in females. In dorsal and ventral views, carapace elongated (length/width c. 1.3) and symmetric. In right lateral view, dorsal margin slightly arched, ventral margin straight and flange absent. Distal lobe of hemipenis acuminated (length superior to width) with basis ending in hook on its internal side and no digital expansion. Short dorsal seta is present on distal lobe ventral side. Hemipenis with copulatory process divided in well distinguishable distal glans and ejaculatory duct, which are similar in length.

Examined material. Two males (MZUSP 37404, MZUSP 37411) and two females (MZUSP 37409, MZUSP 37412) dissected with valves dried and coated for scanning electron microscopy and stored in a micropaleontological slide and appendages mounted on a permanent slide with CMC-9AF mounting medium; a male (MZUSP 37408) and four females (MZUSP 37405, MZUSP 37406, MZUSP 37407, MZUSP 37410) dried and coated for scanning electron microscopy and stored in a micropaleontological slide; a male and seven females kept whole in a vial with 70% ethanol (MZUSP 37413).

Examined material locality. Tank-bromeliads from Saint Andrew Parish, Jamaica. Approximate geographical coordinates 18º05'N, 76º89'W collected in February and March 1991 by Paul D. N. Hebert.

Description of male. Carapace ( Fig. 20 ). Medium-sized carapace (length= 0.72 mm). Color varying from light to dark brown, surface with sparse setae and normal pore canals. Strong ornamentation composed by individual and deep concavities. In dorsal and ventral views, carapace elongated and posterior end slightly acuminate. Dorsal and ventral margins straight in dorsal and ventral views. In right lateral view, carapace also elongated, dorsal margin slightly arched and ventral margin straight. Left valve overlapping right one on all margins.

Left valve ( Fig. 20 J–M). Selvage well-marked on all carapace extension, forming bow funnel-shaped structure on the oral region. Flange well developed in anterior, ventral and posterior regions, the latter bearing several tiny and sparse setae. Vestibule in both anterior and posterior regions.

Right valve ( Fig. 20 N–P). Selvage well-marked on all valve extension forming bow funnel-shaped structure on oral region. Flange also present and well developed in anterior, ventral and posterior regions, the latter bearing small sparse setae. Vestibule in both anterior and posterior regions. Hinge, a bar with two proto-teeth, posterior one more pronounced. Adductor muscle scars four stacked spots.

Antennula ( Fig. 21A (represented by female specimen), 22A). Five-segmented. First segment relatively long bearing sub-apical expansion with tuft of tiny pseudochaetae. Second segment the longest and with single plumose seta in ventro-apical position reaching fourth segment. Third segment small and subquadrate, with single serrate seta in dorso-apical position reaching fourth segment at about mid-length. Fourth segment bigger in length than in width and partially subdivided slightly before mid-length, bearing two serrate dorso-apical setae with almost equivalent lengths, a serrate ventro-apical seta and apically a very long serrate ventro-apical seta and three serrate dorso-apical setae: two short and one long with length equivalent to that of ventro-apical seta. Fifth segment (terminal) with three serrate and thin setae, one long and two equally short, plus aesthetasc (Ya). Third, fourth and fifth segments with a row of pseudochaetae covering whole or part of their apical portions. All setae with constrictions.

Antenna ( Fig. 22B ). Protopodite consisting of two segments; coxa ring-shaped and basis long and arched, dorsally with two rows of pseudochaetae and triangular-shaped group of pseudochaetae. Endopodite three-segmented; first segment relatively short with very long serrate seta in ventro-apical position beginning from expansion of segment and reaching second segment apical portion, ventrally a group of pseudochaetae in triangular shape and dorsally three separated groups of long pseudochaetae, with each group reaching next one. Second segment long with length greater than width, bearing two dorso-apical setae, one half as long as the other, serrate seta and aesthetasc (Y) in ventro-medial position and apically, two setae: one long, strong and serrated, and one tiny. Third segment (terminal) with three claws of the same length, two serrate and one pectinate with very strong row of denticles, besides tiny seta and hyaline formation. Exopodite very long and arched with very small and tiny seta.

Mandible ( Fig. 21G, H (represented by female specimen), 22D, E). Coxa internally with eight strong teeth, spoon-shaped modified X1 seta and long plumose seta, plus two interdental setae, X2 and X3, three interdental spines and sub-apical plumose seta. Palp divided in four segments: basis and three-segmented endopodite; basis with two setae in subapical position and respiratory plate (the exopodite) bearing three long setae and one short, reflexed seta, all with tiny setules; first endopodial segment bearing two apical setae, one half as long as the other; second endopodial segment with four apical setae, two long and two short; third endopodial segment (terminal) with three setae, two thin and equivalent in length and one larger and longer than other two.

Maxillula ( Fig. 22F ). Bearing three endites, first one with three slender setae equal in length; second and third endites with two spatulate claws and three smooth and slender setae each. Palp with about four rows of tiny pseudochaetae medially-positioned and two long plumose setae equal in length plus very short vestigial seta on its apical portion. Respiratory plate (exopodite) well developed with several tiny spines on its body and 16 rays plus reflexed seta, each with several tiny setules.

First thoracic limb ( Fig. 23A , 24 A–F (represented by female specimen)). Basis long and slightly arched, set with several rows of tiny pseudochaetae, bearing on dorsal margin a medium-sized plumose seta plus two short apical pappose setae with basal portion wrapped by expansion of segment. Exopodite a long plumose seta. Endopodial portion divided in three segments with length greater than width, first one the longest with several long pseudochaetae on both sides and single strong biserrate seta, slightly shorter than second segment; second segment with no seta and third segment (terminal) with strong and arched claw, slightly biserrate on its end and bearing vestigial seta and row of tiny pseudochaetae on its basis. All endopodial segments with rows of pseudochaetae in their apical and lateral portions.

Second thoracic limb ( Fig. 23B , 24 G–I (represented by female specimen)). Similar to first thoracic limb, but total appendage length greater and basis with only one plumose seta on its apical portion, also wrapped by expansion of segment, but incompletely. Bisserate seta of first endopodial segment and second segment equal in length. Third segment (terminal) with strong apical claw, slightly longer and more arched than claw present on first thoracic limb.

Third thoracic limb ( Fig. 23C , 24 J–O (represented by female specimen)). Basis bearing three setae: two slender on dorsal margin, one in medial and one pappose in apical position, plus plumose exopodial seta on ventral margin in medio-proximal position. All three endopodial segments with length greater than width and total length greater than in two other thoracic limbs. First segment with single biserrate seta equal in length to second segment and a little slenderer than its homologous structure in first and second thoracic limbs; second segment with transversal row of pseudochaetae on its lateral portion and no setae; third segment (terminal) bearing extremely long and thin claw with minute vestigial seta on its basis. This terminal claw biserrate as in first and second thoracic limbs, but not only in its end but in approximately 2/3 of its length. All three endopodial segments with rows of tiny pseudochaetae in their apical and lateral portions longer than those of two other thoracic limbs.

Hemipenis ( Fig. 23D ). Large, rounded and muscular, with three main structures: copulatory process and lower ramus (together called copulatory complex) and distal lobe. Copulatory process long, with broad basis and apex distinctly divided into ejaculatory duct and distal glans. Ejaculatory duct and distal glans with similar lengths; ejaculatory duct thin and curved on its apex, distal glans slightly larger than ejaculatory duct but still thin. Copulatory process not wrapped in fold as in Elpidium heberti n. sp., Elpidium litllei n. sp. and Elpidium wolfi n. sp. Lower ramus long, slender and with pointed apex. Distal lobe acuminated with length superior to width and no digital expansion. Internal side slightly concave while greatly convex externally. Basis not broad, ending in hook on its internal side. Dorsal seta slender and tiny considering total distal lobe length. Furcal lobe with two pairs of slender setae filled with numerous pseudochaetae.

Additional description of female. Carapace ( Fig. 25 ). Relatively small-sized carapace (length= 0.76 mm). In dorsal and ventral views, carapace elongated and posterior end broad due to the existence of brooding chamber. Sexual dimorphism greatly evident. Posterior end large and rounded. In right lateral view, carapace elongated with dorsal margin slightly arched and left valve overlapping right one on all margins.

Antenna ( Fig. 21 B–F, 22C). Very similar to homologous appendage in males, but differing on terminal segment with tiny and thin seta, hyaline formation and three biserrate claws with approximately equal length, as opposed to males with two biserrate claws and one pectinate claw.

Abdomen ( Fig. 23E ). End of body a large, rounded structure bearing spine-like seta, genital lobes and furcal lobes. Spine-like seta rigid and placed medially, genital lobe a rounded and rigid structure filled internally with trabeculae, furcal lobe also rounded but not rigid with three setae and covered with numerous pseudochaetae.

Comparison with other Elpidium species. Elpidium laesslei differs from any other Elpidium species by the morphology of both carapace and copulatory process. Unlikely any other Elpidium , it has a strong ornamentation composed of deep concavities, while the general pattern of the genus is a subtle ornamentation, usually marked by minute foveolae, either individual or in groups. The copulatory process is also distinctive by the split of the distal glans and ejaculatory duct, also observed in the other three species described here. However, it differs from them, since its distal glans and ejaculatory duct are approximately equally long, while there is usually a noticeable difference in length for the other species here described. Additionally, the proximal part of the copulatory process is not concealed in a fold of the appendage as occurs in E. littlei n. sp., E. heberti n. sp. and E. wolfi n. sp.

Figures

FIGURE 14. Elpidium wolfi n. sp., A–D, I, male; E–H, female. A—right lateral view (MZUSP 37533); B—right lateral view, detail of the anterior region (MZUSP 37533); C—ventral view (MZUSP 37534); D—dorsal view (MZUSP 37533); E—right lateral view (MZUSP 37530); F—ventral view (MZUSP 37532); G—ventral view, detail of the anterior region (MZUSP 37532); H—dorsal view (MZUSP 37531); I—external surface, showing the ornamentation (MZUSP 37533). Scale bars: A, C–F, H— 200 µm; B–50 µm; G—100 µm; I—20 µm.

FIGURE 15. Elpidium wolfi n. sp., male. A—left valve, internal view (MZUSP 37397); B—right valve, detail of antero-dorsal region (MZUSP 37397); C—right valve, detail of postero-dorsal region (MZUSP 37397); D—left valve, detail of posteroventral region (MZUSP 37397); E—left valve, detail of antero-ventral region (MZUSP 37397); F—right valve, internal view (MZUSP 37397); G—right valve, detail of antero-ventral region (MZUSP 37397); H—right valve, detail of postero-ventral region (MZUSP 37397); I—right valve in oblique view, showing the hinge bar (MZUSP 37397). Scale bars: A, F, I—200 µm; B-E—50 µm; G, H—100 µm.

FIGURE 16. Elpidium wolfi n. sp., A, H, I, male; B–G, J, female.A—antennula, terminal segment, arrow points to the aesthetasc (Ya); B—antenna, terminal segment, arrow points to the vestigial seta present on the second endopodial segment; C—antenna, second endopodial segment, arrow points to the aesthetasc (Y); D—antenna, second endopodial segment, detail of aesthetasc (Y), showing the chemosensorial section; E—antenna, first endopodial segment, arrows point to the groups of pseudochaetae: one, in triangular shape, ventrally placed and three dorsally placed; F—antenna, protopodite, arrows point to the pseudochaetae groups: two rows of tiny pseudochaetae and one group in triangular shape, apically placed; G—mandible, coxa; H—maxillula, endites, arrow points to the spatule-setae constriction; I—maxillula, endites, arrows point to the spatule-setae constrinction and to the rows of pseudochaetae present on the appendage; J—maxillula, palp, arrows point to the rows of pseudochaetae present on the appendage. Scale bars: A, C, G, J—2 µm; B, E, F, H, I—10 µm; D—1µm.

FIGURE 17. Elpidium wolfi n. sp., A, B, E-H, male; C, D, female. A—antennula (MZUSP 37397); B—antenna (MZUSP 37397); C—antenna (MZUSP 37399); D—antenna, terminal segment (MZUSP 37399); E—mandible, basis (MZUSP 37397); F—mandible, respiratory plate (MZUSP 37397); G—mandible, coxa (MZUSP 37397); H—maxillula (MZUSP 37397). Scale bars: A, B, E—0.05 mm; C, D—0.1 mm; F–H—0.01 mm. Ya=aesthetasc on terminal segment of antennula. Y=aesthetasc on second endopodial segment of antenna. hy=hyaline formation on terminal segment of antenna.

FIGURE 18. Elpidium wolfi n. sp., A-E, male; F, female. A—first thoracic limb (MZUSP 37397); B—third thoracic limb (MZUSP 37397); C—second thoracic limb (MZUSP 37397); D—hemipenis (MZUSP 37397); E—hemipenis, detail of copulatory complex and distal lobe (MZUSP 37397); F—abdomen (MZUSP 37401). Scale bars: A–C, E, F—0.05 mm; D—0.1 mm. DL=distal lobe on hemipenis. ds=dorsal seta. cop=copulatory process on hemipenis. vej=seminal vesicle. gl=distal glans. dej=ejaculatory duct. LR=lower ramus. dor=dorsal ridge. mer=medial ridge. ver=ventral ridge.

FIGURE 19. Elpidium wolfi n. sp., A, female; B-F, male. A—first thoracic limb, arrows point to the pseudochaetae groups on the appendage basis; B—first thoracic limb, distal claw, arrows point to the vestigial seta and to the pseudochaetae; C—first thoracic limb, detail of distal claw, arrow points to the vestigial seta; D—third thoracic limb, detail of distal claw showing the rows of pseudochaetae, arrow points to the vestigial seta; E—hemipenis, distal lobe; F—hemipenis, furcal lobe, detail shows the setae present on the appendage. Scale bars: A, B, E, F—10 µm; C, D—2 µm.

FIGURE 20. Elpidium laesslei, male. A—dorsal view (MZUSP 37408); B—dorsal view, detail of anterior region (MZUSP 37408); C—dorsal view, detail of posterior region (MZUSP 37408); D—ventral view (MZUSP 37408); E—ventral view, detail of anterior region (MZUSP 37408); F—ventral view, detail of posterior region (MZUSP 37408); G—right lateral view (MZUSP 37408); H—right lateral view, detail of anterior region (MZUSP 37408); I—right lateral view, detail of posterior region (MZUSP 37408); J—left valve, internal view (MZUSP 37404); K—left valve, internal view, detail of anterior region (MZUSP 37404); L—left valve, internal view, detail of posterior region (MZUSP 37404); M—left valve, internal view, detail of posterior region showing the flange with sparse pseudochaetae (MZUSP 37404); N-right valve, internal view (MZUSP 37404); O—right valve, internal view, detail of anterior region (MZUSP 37404); P-right valve, internal view, detail of posterior region (MZUSP 37404). Scale bars: A, D, G, J, N, P—100 µm; B, C, F, H, I, K-M, O—20 µm; E—10 µm.

FIGURE 21. Elpidium laesslei, female.A—antennula, detail of first segment, arrows point to the sub-apical expansion (MZUSP 37412); B—antenna, detail of first segment of protopodite (coxa), arrow points to the row of pseudochaetae (MZUSP 37412); C—antenna, detail of second segment of protopodite, arrows point to the numerous rows of pseudochaetae and to the terminal group of pseudochaetae in triangular shape (MZUSP 37412); D—antenna, first endopodial segment, arrows point to the three groups of pseudochaetae (MZUSP 37412); E—antenna, detail of first endopodial segment, arrow points to the group of ventrally placed pseudochaetae in triangular shape (MZUSP 37412); F—antenna, third endopodial segment, arrow points to the tiny vestigial seta (MZUSP 37412); G—mandible, coxa (MZUSP 37412); H-mandible, coxa, arrow points to the interdental X1, X2 and X3 setae (MZUSP 37412). Scale bars: A-C, F, G—10 µm; D, E—5 µm; H—2 µm.

FIGURE 22. Elpidium laesslei, A, B, D–F, male, C, female. A—antennula (MZUSP 37404); B—antenna (MZUSP 37404); C—antenna (MZUSP 37409); D—mandible, coxa and palp (MZUSP 37404); E—mandible, respiratory plate (MZUSP 37404); F—maxillula (MZUSP 37404). Scale bars: A, B, C—0.05 mm; D–F—0.01 mm. Ya=aesthetasc on terminal segment of antennula. Y=aesthetasc on second endopodial segment of antenna. hy=hyaline formation on terminal segment of antenna.

FIGURE 23. Elpidium laesslei, A–D, male, E, female. A—first thoracic limb (MZUSP 37404); B—second thoracic limb (MZUSP 37404); C—third thoracic limb (MZUSP 37404); D—hemipenis (MZUSP 37411); E—abdomen (MZUSP 37409). Scale bars:A–C, E: 0.05 mm; D—0.1 mm. DL= distal lobe on hemipenis. ds=dorsal seta. cop=copulatory process on hemipenis. vej=seminal vesicle. gl=distal glans. dej=ejaculatory duct. LR=lower ramus. dor=dorsal ridge. mer=medial ridge. ver=ventral ridge.

FIGURE 24. Elpidium laesslei, female. A—first thoracic limb, arrows point to the numerous pseudochaetae present on the protopodite segment (MZUSP 37410); B—first thoracic limb, detail of protopodite and first endopodial segment, arrows point to the segment expansion that involves the basis of the two protopodite setae and to the group of long pseudochaetae laterally placed on the first endopodial segment (MZUSP 37410); C—first thoracic limb, detail of the segment expansion that involves the whole width of the two protopodite setae (MZUSP 37410); D—first thoracic limb, detail of first and second endopodial segments, arrows point to the two groups of short pseudochaetae placed near to the end of the two segments (MZUSP 37410); E—first thoracic limb, detail of third endopodial segment and distal claw, arrows point to the rows of pseudochaetae transversely placed on the segment and claw (MZUSP 37410); F—first thoracic limb, detail of the distal claw, arrow points to the rows of pseudochaetae involving its ending (MZUSP 37410); G—second thoracic limb, arrows point to the pseudochaetae on the protopodite and to the long pseudochaetae laterally placed on the first endopodial segment (MZUSP 37410); H-second thoracic limb, detail of the distal claw, arrow points to the rows of pseudochaetae involving its ending (MZUSP 37410); I—second thoracic limb, detail of third endopodial segment and distal claw, arrows point to the rows of pseudochaetae transversely placed on the segment and claw (MZUSP 37410); J—third thoracic limb, arrow points to the long pseudochaetae laterally placed on the first endopodial segment (MZUSP 37410); K—third thoracic limb, detail of protopodite, arrows point to the two rows of pseudochaetae present on the segment, the last one involving the basis of the seta (MZUSP 37410); L-third thoracic limb, detail of protopodite basis, arrow points to the segment expansion that involves the apical seta basis (MZUSP 37410); M—third thoracic limb, detail of second endopodial segment, arrows point to the rows of pseudochatae that transect the segment (MZUSP 37410); N—third thoracic limb, detail of third endopodial segment, arrow points to the rows of pseudochaetae that transect the segment (MZUSP 37410); O—third thoracic limb, detail of distal claw, arrows point to the rows of pseudochaetae that involve the end of the claw (MZUSP 37410). Scale bars: A, B, D, G, J, O—10 µm; C, F, H, I, K—1 µm; E, L–N—2 µm.

FIGURE 25. Elpidium laesslei, female. A—dorsal view (MZUSP 37406); B—dorsal view, detail of anterior region (MZUSP 37406); C—dorsal view, detail of posterior region (MZUSP 37406); D—ventral view (MZUSP 37405); E—ventral view, detail of anterior region (MZUSP 37405); F—ventral view, detail of posterior region (MZUSP 37405); G—right lateral view (MZUSP 37407); H—right lateral view, detail of anterior region (MZUSP 37407); I—right lateral view, detail of posterior region (MZUSP 37407); J—left valve, internal view (MZUSP 37412); K—left valve, internal view, detail of anterior region (MZUSP 37412); L—left valve, internal view, detail of posterior region (MZUSP 37412); M—right valve, internal view (MZUSP 37412); Nright valve, internal view, detail of anterior region (MZUSP 37412); O—right valve, internal view, detail of posterior region (MZUSP 37412); P—dorsal view, detail of ornamentation (MZUSP 37406). Scale bars: A, D, G, J, L, M—100 µm; B, C, E, F, H, I, K, N, O—20 µm; P—10 µm.