Eluma matae, Cifuentes & Da Silva, 2023

Cifuentes, Julio & Da Silva, Luis P., 2023, The genus Eluma in the Iberian Peninsula, with the description of a new terrestrial isopod: Eluma matae sp. nov. (Oniscidea, Armadillidiidae, Eluminae), European Journal of Taxonomy 860 (1), pp. 27-41 : 33-36

Eluma matae sp. nov.

urn:lsid:zoobank.org:act:F2B036D0-A18A-483B-A27F-E9832E2A9B48

Figs 1B , 3 , 4A–F, I–Q

Diagnosis

Dorsum of pereon and pleon are smooth with circular or oval depressions covered with hair like structures formed by scale-setae of diverse shapes and sizes. The volvation is of the euspheric type. The eye apparatus is formed by a large ocellus. The cephalon is of the elumean type and has a large schisma on the side edge of the first pereonite. In the male, the carpus of the pereopod I has a brush of setae and hyaline scales on the ventral side; the ischium of the 7 th pereopod has a caudal crest ending in a rounded dilation.

Etymology

This species is dedicated to Dr Vanessa A. Mata, from CIBIO-InBIO/BIOPOLIS, University of Porto, Portugal, for her support during the work that allowed the discovery and description of this new species.

Type material

A total of 15 specimens were analysed, 4 males and 11 females

Holotype PORTUGAL • ♂; Leiria, Ermida de Santo Antão ; 39°22′25″ N, 9°09′46″ W; 56 m a.s.l.; 1 May 2022; L.P. da Silva leg; INV16027 .

Paratypes

PORTUGAL – Leiria • 1 ♀; A-da-gorda ; 39°20′53″ N, 9°09′30″ W; 55 m a.s.l.; 13 Apr. 2022; L.P. da Silva leg; INV16015 • 1 ♀; A-da-gorda ; 39°20′54″ N, 9°09′31″ W; 52 m a.s.l.; 13 Apr. 2022; L.P. da Silva leg; INV16016 • 1 ♂; Ermida de Santo Antão; 39°22′15″ N, 9°09′39″ W; 57 m a.s.l.; 12 Mar. 2022; L.P. da Silva leg; INV16006 • 1 ♂; same collection data as for holotype; JC636 • 1 ♀; same collection data as for holotype; INV16029 • 1 ♀; same collection data as for holotype; INV16026 • 1 ♀; same collection data as for holotype; MNCN 20.04/20266 • 1 ♀; same collection data as for holotype; INV16028 • 1 ♂; Óbidos ; 39°21′48″ N, 9°09′22″ W; 48 m a.s.l.; 30 Apr. 2022; L.P. da Silva leg; MNCN 20.04/20265 • 1 ♀; same collection data as for preceding; INV16023 • 1 ♀; Óbidos ; 39°21′48″ N, 9°09′21″ W; 42 m a.s.l.; 30 Apr. 2022; L.P. da Silva leg; INV16024 • 1 ♀; Óbidos ; 39°21′47″ N, 9°09′21″ W; 44 m a.s.l.; 30 Apr. 2022; L.P. da Silva leg; INV16025 • 1 ♀; same collection data as for preceding; JC635 . – Santarém • 1 ♀; Mata de Baixo ; 39°22′39″ N, 8°58′20″ W; 176 m a.s.l.; 13 Mar. 2022; L.P. da Silva leg; INV16007 .

Description

Maximum length: 12 mm.

General coloration purplish brown to dark green, muscle attachments very marked ( Fig. 3A–D ); pereon with large whitish spot at limit of epimera ( Fig. 3C ); same pattern repeated in pleon.

Integumentary characters

– Dorsum of cephalon, pereon and pleon smooth, with large number of circular or oval depressions ( Fig. 3E ) and small striated scales.

– Scale-setae: body covered by hair like structures composed by large number of scale-setae of various shapes, some with Y shape with different sizes ( Figs 3E , 4A–D ), always long or very long and sharp or dilated at tip; others very wide, with rectangular appearance ( Fig. 4E ) and finally some very characteristic scale-setae, long (0.14 mm), wide and mace-shaped ( Figs 3F , 4F ), very visible in specimens ( Fig. 3A– D ), these scale-setae arranged in five or six rows on cephalon and on first tergite of pereon ( Fig. 3A–B ), three rows between 2 nd and 7 th segments, one row in 1 st and 2 nd segments of pleon, 2 rows in segments 3 rd to 5 th and 3 rows in telson ( Fig. 3D ). Among them is rest of scale-setae types.

Somatic characters

– Body: volvation of euspheric type ( Fig. 3A ).

– Eye apparatus formed by large ocellus with very refringent cornea ( Fig. 3C ).

– Cephalon ( Figs 3B , 4I ): elumean type, without post-scutellar line, posterior edge of cephalic shield directly continuous with frontal line. Cephalic shield big and wide, and frontal cephalic lamina clearly stands out above vertex. Antennal lobes very salient and have very short posterior segment. Posterior edge not raised.

– Pereon ( Fig. 3A–C ): tergites posterior edge not raised. First tergite with edge very sinuous and lateral edge has large schisma, which two very differentiated lobes, with lower standing out in relation to upper lobe and large separating groove between both edges. Remain epimera almost vertical until upper side and quadrangular with rounded edges, except fourth epimera, more triangular.

– Pleon ( Fig. 3D ): ogival shape, with slightly oblique neopleurons.

– Telson ( Fig. 3D ): triangular with straight edges and slightly rounded tips.

Appendages

– Mouth apparatus as the rest of species of Eluma .

–Antennules ( Fig. 4J ): three segments, second smaller than other two; third has group of small aesthetascs at tip.

– Antennae ( Fig. 4K ): long and thin, and fifth segment longer than antennal flagellum. Second flagellum segment two and a half times as long as first and has three groups of very small aesthetascs.

– Uropods ( Fig. 4D ): endopods cylindrical and exceed end of telson. Exopods trapezoidal and much wider than long.

Male sexual characters

– Pereopod 1 ( Figs 3G–H , 4L ): carpus with lax brush of long setae and numerous hyaline scales on ventral side.

– Pereopod 7 ( Figs 3I , 4M ): ischium very long, with straight sternal margin and terminal crest ending in large dilatation with rounded tip. Merus lacks differentiation.

– Pleopod I: endopod ( Figs 3J , 4N ) long and curves slightly outwards in middle, ending in very wide point with several folds. Exopod ( Figs 3K , 4O ) has very marked inner tip, triangular, curved, with inner side broadly rounded and outer side straight.

– Pleopod II: endopod ( Fig. 4P ) very long, fine and exceeds extreme of exopod. Exopod ( Figs 3L , 4Q ) triangular, with rectangular base and very large triangular inner tip.

Ecology

All specimens were found in limestone areas from the Jurassic Period, below rocks, usually with a high amount of plant debris. They were also found only in places with natural vegetation, namely with Q. faginea . Most specimens were captured together with Ctenoscia minima ( Dollfus, 1892) and Porcellio dispar Verhoeff, 1901 .

Figures

Fig. 1. Map of location of the Iberian Peninsula and maps with the geographic distribution of the species of Eluma (bibliographical references with red triangle; material studied with blue triangle). A. E. caelata (Miers, 1877). B. E. matae sp. nov. C. E. tuberculata Cruz, 1991.

Fig. 3. Eluma matae sp. nov., paratype, ♂ (INV16006). A. Habitus, side view. B. Cephalon and first pereonite, frontal view. C. First pereonite, side view. D. Pleon, telson and uropods. E. Dorsal tegument and scale-setae. F. Scale-setae, detail. G. Carpus of the pereopod 1. H. Carpus of the pereopod 1, setae. I. Pereopod 7, ischium. J. Tip of endopod I. K. Exopod I. L. Exopod II. Scale bars: A = 1 mm; B–D = 0,5 mm; E, F, H = 0.05 mm; G, I–L = 0.1 mm.

Fig. 4. Eluma matae sp. nov. A–F, I, K–Q. Paratype, ♂ (INV16006). J. Paratype, ♀ (INV16007). A–F. Scale setae. G. E. caelata (Miers, 1877), ♂ (CCZ-UGR852), scale setae. H. E. tuberculata Cruz, 1991, ♀ (INV16004), scale setae. I. Cephalon and first pereonite, frontal view. J. Antennule.K. Antenna. L. Pereopod 1. M. Pereopod 7. N. Endopod I. O. Exopod I. P. Endopod II. Q. Endopod II.