Cleantioides pandemus, Negromonte & Lucatelli & Paiva & Souza-Filho, 2022

Negromonte, Aurinete Oliveira, Lucatelli, Debora, Paiva, Ricardo José de Carvalho & Souza-Filho, Jesser F., 2022, Three new species of the genus Cleantioides Kensley and Kaufman, 1978 (Isopoda: Valvifera) from Brazil, with new record of the family Holognathidae from Brazil, Journal of Natural History 56 (13 - 16), pp. 923-941 : 930-934

Cleantioides pandemus sp. nov.

( Figures 5–8 )

Type material

Holotype. Male (2.7 mm), Tamandaré Bay , Pernambuco (8.77°S, 35.09°W), #2 light trap, 25 September 2014, MOUFPE 20060 .

Paratypes. 1 male, same as holotype, #2 light trap, 3 October 2013, MOUFPE 20061 . 1 male, same as holotype, #1 light trap, 21 July 2012, MOUFPE 20062 . 1 male, same as holotype, #2 light trap, 25 September 2014, MOUFPE 20063 .

Diagnosis. Body 5.6x longer than wide, lacking plumose setae. Antenna 2 article 2 with a ventromesial process with bilobed apex and much longer than dorsalmesial process. Pereopod 4 propodus with a robust seta tridentate distally; dactylus without unguis and with rounded tip. Pleotelson dorsally almost straight, 0.3x total body length, 1.9x longer than wide; dorsum of distal half with oblique circular plane inclined ~20° from horizontal, occupying 0.44 of pleotelson length, well defined by a sharp marginal ridge extending all around, with 2 submedian poorly developed rounded-edged lobes dorsally separated by a very faint furrow, followed by 2 submedian longitudinal rounded ridges (best seen in lateral view). Ridges not reaching posterior margin.

Description. Based on holotype.

Body 5.6x longer than wide, dorsal densely rugose. Head 1.5x wider than long, with anteromesial excavated depression; posterior margin convex. Eyes dorsolateral, reniform. Coxae 5–7 and epimeral plates 1–4 without plumose setae on posterior margin. Pleotelson 0.3x total body length, 1.9x longer than wide, lacking setae. Pleonite 1 free and articulated, barely visible under pereonite 7. Pleonites 2–3 well defined but not articulated, pleonite 4 fused medially only, lateral margin hidden under pleonite 2; remaining pleotelson parallel-sided and with semicircular apex; dorsum of distal half with oblique circular plane inclined ~20° from horizontal, occupying 0.44x of pleotelson length, well defined by a sharp marginal ridge extending all around, dorsally with 2 submedian poorly developed rounded-edged lobes separated by a very faint furrow, followed by 2 submedian longitudinal rounded ridges (best seen in lateral view); ridges not reaching posterior margin.

Antenna 1 reaching ~1/3 of article 3 of antenna 2 peduncle; peduncle article 1 1.2x wider than long; flagellum ~4/5 length of article 3 peduncle, with 3 apical plumose setae. Antenna 2 0.26x length of body, article 2 with a ventromesial process with bilobed apex and much longer than dorsalmesial process; flagellum 1 articulated, 0.22x total antenna length, and a tuft of setae distally. Mandible molar columnar and triturative; right incisor with 3 teeth, right lacinia mobilis with 3 teeth, and left with 5 teeth. Maxilla 1 outer plate without a row of setules, distal margin with 6 robust setae, inner plate shorter than outer plate, bearing 2 robust and plumose setae distally. Maxilla 2 outer plate with an oblique row of 11 plumose setae; middle and inner plate with a row of 7 and 8 plumose setae, respectively. Maxillipedal endite with 2 robust setae on lateral margin, 6 slender setae distally and 3 on transverse apex; palp width 0.37x length, 5 visible articles; articles 2–5 setose mesially; article 3 lobed mesiodistally; article 5 wider than long, 0.25x length of article 4; epipod tapering and rounded distally.

Pereopod 1 basis with setose dorsal margin; ventral margin of merus with only 1 robust seta, carpus and propodus with dense robust setation; propodus almost 2x longer than wide. Pereopods 2 and 3 similar, basis without setae on ventral margin, dorsal margin with a proximal tuft of slender setae; ischium longer than merus, distal margin widened, with a robust seta on dorsodistal angle (pereopod 2 with a robust seta on ventrodistal angle); merus with dorsodistal angle slightly produced; carpus and propodus with robust setae on ventral margin; carpus shorter than propodus, with a line of robust setae on ventral margin, dorsal margin of pereopod 3 lacking setae; propodus longer than wide (2.4x pereopod 2 and 2.9x pereopod 3), with a line of robust setae on ventral margin, dorsal margin of pereopod 3 with a line of slender setae; dactylus well developed, curved and bearing a distal unguis. Pereopod 4 0.45x length of pereopod 3, ischium with 2 robust setae; merus, carpus and propodus with posterodistal U-shaped rows of 10, 12, and 8 robust setae, respectively; propodus with a robust seta tridentate distally; dactylus without unguis and with rounded tip. Pereopod 5 longer than 4, basis, ischium and merus with a row of long slender setae on dorsal margin; carpus ventral margin with a single robust seta; ventral margin dactylus slightly hooked. Pereopods 6 and 7 more elongate than 5, basis, ischium and merus with a row of long slender setae on the dorsal margin; propodus of pereopod 7 3.1x longer than wide. Penes near base of uropod, on ventrum of pereonite 7, rami 1.2x basal width, separate and tapering to rounded apices. Pleopod 1 peduncle with 3 robust setae; inner ramus longer than outer ramus (1.3x). Pleopod 2 peduncle with 3 robust setae; inner ramus longer than outer ramus (1.3x); outer ramus subrectangular with apex truncate, outer margin smooth. Appendix masculina inserted mesially and slightly surpassing distal margin of inner ramus (in development). Uropodal peduncle 2.8x longer than wide; endopod almost as wide as long, rounded distally.

Etymology. The species epithet pandemus relates to the global pandemic starting in 2020 caused by the virus SARS-CoV-2. During this time the new species was recognised and described by the authors.

Remarks. Cleantioides pandemus sp. nov. is closely related to C. bruscai and C. occidentalis by the structure of the subcircular part of the pleotelson. However, it is readily distinguished from both species by the poorly developed rounded-edged lobes (vs strongly developed in C. bruscai and C. occidentalis ); these lobes are separated by a very faint furrow, followed by 2 submedian longitudinal rounded ridges (vs absent in C. bruscai and C. occidentalis ).

Figures

Figure 5. Cleantioides pandemus sp. nov. Male (2.7 mm), Tamandaré Bay, Pernambuco (8.77°S, 35.09° W), MOUFPE 20060. Abbreviation: Hb, habitus. Scale bars: 0.5 mm.

Figure 6. Cleantioides pandemus sp. nov. Male (2.7 mm), Tamandaré Bay, Pernambuco (8.77°S, 35.09° W), MOUFPE 20060. Abbreviations: A, antenna; Md, mandible; Mx, maxilla; Mxp, maxiliped. Scale bars: 0.1 mm.

Figure 7. Cleantioides pandemus sp. nov. Male (2.7 mm), Tamandaré Bay, Pernambuco (8.77°S, 35.09° W), MOUFPE 20060. Abbreviation: P, pereopod. Scale bars: 0.1 mm.

Figure 8. Cleantioides pandemus sp. nov. Male (2.7 mm), Tamandaré Bay, Pernambuco (8.77°S, 35.09° W), MOUFPE 20060. Abbreviation: P, pereopod; Pl, pleopod; PP, penile papillae; Ur, uropod. Scale bars: 0.1 mm.