Santaremicaris, Santos-Silva, 2021

Santos-Silva, Paulo Henrique Costa Corgosinho Carlos Eduardo Falavigna da Rocha Pedro Martínez Arbizu Edinaldo Nelson dos, 2021, A new genus of Parastenocarididae Chappuis, 1940 (Copepoda: Harpacticoida) from the Amazonian Region, Brazil, with close affinity to Murunducaris Reid, 1994, Nauplius (e 2021015) 29, pp. 26-26 : 5-6

Santaremicaris gen. nov.

ZooBank: urn:lsid:zoobank.org:act:27524A69-87E4-4634-A626-62D514F995A1

Diagnosis. Small-sized Fontinalicaridinae (255−325 μm), with cylindrical habitus; body cuticle poorly chitinised; dorsal integumental window on Cph, Urs 3−5 in male and Urs 2−4 in female; boundary between prosome and urosome inconspicuous; Gf a wide concave plate, two times wider than narrow, with medial process and occupying anterior ventral half of female Gds. Last Urs of males and females with undulate distal frill. Fu cylindrical, divergent, about three times as long as wide, armed with six setae(Setae I, III, IV, V, VI, and VII), with distinct gap between setae I−III and VII, setae I and III inserted in proximal third of furca, seta VII in distal third; seta I longer than seta III, seta II absent, seta IV distally inserted on outer margin, longer than setae I, III, VI and VII, seta V the longest, about 4 times longer than Fu. Antennule eight-segmented in male and seven-segmented in female. A1 of the coiled type, segments V−VIII of males forming a functional unit for clasping the female. Coxal gnathobasis of md with distal row of teeth and seta; md palp one-segmented, with two distal setae. Mx1praecoxal arthrite with five elements (surface seta thick and blunt, three claw-like pinnate spines, and slender seta); coxal endite with one seta; basis with three setae. Mx allobasis with two endites; proximal endite with one seta; distal endite with two smooth setae and serrate spine; proximal endopodal segment drawn out into claw; distal endopodal segment with two setae. Mxp subchelate; syncoxa about 1/3 length of basis; enp drawn into spinulose claw. Basis of P1 sexually dimorphic in male, with modified robust spinule or row of strong spinules on inner margin; with outer seta. Male P2 enp with long distal seta, the insertion area of it covering almost the whole width of the segment, without distal ornamentation and with strong ornamentation on outer margin, along the first 2/3 of the segment. Male P3 with rectangular, smooth or ornamented coxa; basis rectangular or trapezoidal, approximately twice as long as wide, with long row of spinules on inner margin; with hook-like spinule on proximal inner margin or without it; enp absent; exp one-segmented, rectangular with regular margins or with irregular margins and tapering distally, longer than wide, slightly curved inwards, weakly ornamented on outer margin or smooth, with or without tube pore on inner margin; apophysis without distal seta or spine, spatuliform and shorter than thumb or slightly longer than thumb, the apophysis ending in a long tip with a rounded hyaline cushion at tip; thumb with or without hyaline inner margin. Female P3 enp unarmed, shorter than exp1 and acuminate distally. Male P4 basis unornamented, with outer seta and outer pore; inner margin of male P4 exp1 with distal and proximal row of spinules; enp short, triangular, not reaching middle of exp1, smooth or ornamented on outer margin, with strongly chitinized regions. Female P4 enp one-segmented, slightly longer than exp1 and bearing one distal and bipinnate spine fused to segment, ornamented with spinules on distal half, near the fusion of the spine and the enp. Male P5 a well-developed triangular plate reaching middle of next somite or slightly beyond; with irregular margins; inner margin with row of small spinules; distal portion ending in strong spiniform process; armature consisting of very long outer basal seta and two additional setae; intercoxal sclerite enlarged, triangular or a trapezoid plate, longer than wide, with distomedial cuticular process. Female P5 with small distal spiniform process, shorter than in male, long outer seta and three well-developed lateral setae; with a small triangular intercoxal sclerite. P6 an unarmed concave plate with median hump covering Gf.

Type species. Parastenocaris santaremensis Noodt,

1963.

Composing species. Santaremicaris santaremensis

( Noodt, 1963) comb. nov.; S. amazonensis sp. nov.

Etymology. The generic name refers to Santarém (Pará, Brazil), the municipality in which the new species were collected, combining this name with the ancient Greek substantive for shrimp, κΑΡίς (caris).

Autapomorphies for the genus. Male second urosomite without integumental window. Last Ur of males and females with undulate distal frill. P2 enp without distal ornamentation, with long distal seta, the insertion area of it covering almost the whole width of the segment, and strong outer ornamentation along the first 2/3 of the segment. Basis of male P3 with long row of spinules on the inner margin. Absence of male P3 enp. Short, triangular and strongly chitinized male P4 enp. Long and slim male P5 with irregular margins, reaching the middle of the next urosomite or beyond, distal portion ending in a strong spiniform process, ornamented with spinules on the inner margin, armed with only three setigerous elements on the outer margin.