Eluma cristata, Eusébio & Taiti & Reboleira, 2025

Eluma cristata sp. nov.

Figs 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 K View Figure 6

Eluma tuberculata Reboleira et al., 2015: 49 (partim: specimens from MSS near Gruta de Alcobertas, Estremenho Karst Massif). View in CoL

Type material.

Holotype. Portugal • ♂; Alcobertas ; 39°25'46.5"N, 8°54'59.0"W; 21.VII.2022; leg. R. P. Eusébio; MSS pitfall trap; MNHNC: MB 11: 001198 GoogleMaps . Paratypes: Portugal • 137 ♂♂, 138 ♀♀; same data as holotype; MNHNC: MB 11: 001186 , 001189, 001195, 001198, 001200 GoogleMaps • 115 ♂♂, 121 ♀♀; 20.IX.2022; same data as for preceding; MNHNC: MB 11: 001203 , 001207, 001209, 001213, 001216 GoogleMaps • 5 ♂♂, 10 ♀♀; same data as for preceding; MZUF 10038 View Materials GoogleMaps • 280 ♂♂, 240 ♀♀; 20.XII.2022; same data as for preceding; MNHNC: MB 11: 001291 , 001295, 001296, 001301, 001302 GoogleMaps • 10 ♂♂, 10 ♀♀; same data as for preceding; MZUF 10039 View Materials GoogleMaps • 68 ♂♂, 103 ♀♀; 1.IV.2023; same data as for preceding; MNHNC: MB 11: 001348 , 001351, 001354, 001356 GoogleMaps .

Description.

Maximum length: ♂ 7.5 mm; ♀ 9.5 mm. Body strongly convex, able to roll up into perfect ball, euspheric type. Colour light brown, as in E. matae and E. tuberculata . Dorsal surface with ornamentation consisting of protruding crests on posterior margins of cephalon, pereonites 1–7 tergites and median part of pleonites 1–5, each crest ending in lobes of irregular shape and number; telson with two small paramedian tubercles (Figs 2 A – E View Figure 2 , 3 A, G, H View Figure 3 , 6 K View Figure 6 ). Dorsum with scattered pointed scale-setae (Fig. 3 B View Figure 3 ) and one line of noduli laterales per side located near top of crests on pereonites 1–7 far from lateral margins (Fig. 3 G View Figure 3 ). Cephalon (Figs 2 A – D View Figure 2 , 3 A View Figure 3 , 6 K View Figure 6 ) with triangular scutellum distinctly separated from and not bent over vertex; distinct frontal line and no postscutellar line; oblique antennary lobes, quadrangular and directed frontwards. Eye consisting of single large ocellus as in Fig. 2 A, C View Figure 2 . Pereonite 1 (Figs 2 A, C View Figure 2 , 3 C, D View Figure 3 , 6 K View Figure 6 ) with deep dorsal groove on lateral margin, schisma on posterior corners with rounded inner lobe distinctly shorter than outer lobe; posterior margin slightly concave at sides. Pereonites 2 and 3 (Fig. 3 E, F View Figure 3 ) epimera quadrangular with small and rounded lobe on ventral side. Pereonites 4–7 with quadrangular epimera and straight posterior margins. Pleonites 3–5 (Fig. 3 G View Figure 3 ) with rectangular epimera, slightly divergent. Telson (Fig. 3 G, H View Figure 3 ) triangular, wider than long, with slightly concave sides and rounded apex. Antennula (Fig. 3 I View Figure 3 ) of three articles, second article much shorter than first and third, third article with tuft of superimposed aesthetascs subapically. Antenna (Fig. 4 A View Figure 4 ) with flagellum slightly shorter than fifth article of peduncle, second flagellar article more than twice as long as first, bearing two aesthetascs on middle part. Mandibles (Fig. 4 B, C View Figure 4 ) with dichotomized molar penicil and three or four free penicils; right mandible with one penicil and left mandible with two penicils on hairy lobe. Maxillula (Fig. 4 D View Figure 4 ) outer lobe with 4 + 6 (5 cleft) teeth; inner lobe with two thick subapical penicils and small triangular distal point. Maxilla (Fig. 4 E View Figure 4 ) apically setose with outer lobe rounded, much wider than inner lobe. Maxilliped (Fig. 4 F View Figure 4 ) with quadrangular endite bearing two triangular spines on distal margin and large subapical seta; basal article of palp with two large setae. Uropod (Fig. 4 G View Figure 4 ) flattened; exopod about twice as wide as long with slightly concave distal margin; endopod slightly protruding backwards compared with exopod.

Male. Pereopod 1–3 (Fig. 5 A View Figure 5 ) with line of pointed setae on sternal margins of carpus and, to lesser extent, merus. Pereopod 7 (Fig. 5 B View Figure 5 ) ischium with sternal margin distinctly concave, distal margin with rounded lobe and four stout setae; merus with sternal margin slightly convex; merus and carpus with line of long setae on sternal margin. Genital papilla (Fig. 5 C View Figure 5 ) fusiform. Pleopod 1 (Fig. 5 C View Figure 5 ) exopod with large distal lobe bent outwards and apically rounded; endopod with distal part quadrangular and short apical lobe directed outwards. Pleopod 2 (Fig. 5 D View Figure 5 ) exopod triangular with a line of about five short setae on outer margin; endopod slightly longer than exopod. Pleopods 3–5 exopods as in Fig. 5 E – G View Figure 5 .

Etymology.

From Latin cristatus = crested. The name refers to the high crests on the posterior margins of the body segments.

Remarks.

At present, the genus Eluma comprises only five species, i. e., the four species included here and E. praticola Taiti & Rossano, 2015 from northern Morocco (see Schmalfuss 2003; Taiti and Rossano 2015; Cifuentes and Da Silva 2023). Eluma cristata sp. nov. is readily distinct from all the other species by the protruding dorsal crests on the posterior margins of the cephalon, pereonites and, to a lesser extent, pleonites. Moreover, it differs from E. caelata in lacking the basal triangular lobe on the male pereopod 7 merus (see fig. 32 F, G in Taiti and Rossano 2015); from this species and E. praticola also in the male pleopod 1 endopod with thickset distal part, not bent outwards; from E. matae also in the much shorter dorsal scale-setae of different shape (see fig. 4 A – F in Cifuentes and Da Silva 2023).

Ecological notes.

This species was only found in this MSS habitat.

Seasonal patterns in Portuguese MSS habitats.

This species was only found in Alcobertas, during all seasons, and with a decrease in abundance from spring to summer, highest abundance during fall and a new decrease in winter (Fig. 7 K View Figure 7 ).