Thor paulae, Kochenborger, 2022

Thor paulae sp. nov.

( Figs. 1 View Figure 1 , 2 View Figure 2 )

Zoobank: urn:lsid:zoobank.org:pub:E6AC08C7-EE6E-4EBB-B6BD-F1B2250C8255

Type material. Panama: Holotype, ovigerous female (CL 2.7 mm), UF 60011 , Panama, Bocas del Toro, Seagal (09°17’20.4”N 82°17’45.6”W), colls. M. Leray, F. Michonneau and R. Lasley, 27 May 2016 GoogleMaps . Paratypes: 1 male with appendix masculina and 8 females (6 ovigerous and 2 non-ovigerous adults, CL 2.2–2.7 mm), UF 44518 (photo available, one dissected specimen), same data as holotype GoogleMaps ; 1 male with appendix masculina (CL 1.9 mm), UF 44289 , Panama, Bocas del Toro, Ponsak (09°17’38.4”N 82°19’55.2”W), colls. M. Leray, F. Michonneau and R. Lasley, 13 May 2016 GoogleMaps ; 7 females (5 ovigerous and 2 non-ovigerous adults, CL 2.0– 2.5 mm), UF 44393 (photo available, one dissected specimen), Panama, Bocas del Toro, Punta STRI ( Smithsonian Tropical Research Institute ) (09°20’56.4”N 82°15’46.8”W), colls. M. Leray, F. Michonneau and R. Lasley, 09 May 2016 GoogleMaps .

Etymology. The new species is named in honor of our great friend, Dra. Paula Beatriz de Araujo (Federal University of Rio Grande do Sul, Brazil), who has devoted her career to the study of biology, ecology, and systematics of crustaceans.

Diagnosis. Supraorbital tooth vestigial or absent. Pterygostomial margin angular, with one tooth. Telson with 3 pairs of dorsolateral spiniform setae; posterior margin with 3 pairs of simple setae. Merus of first pereopod with 1 or 2, rarely 3 or 4, spiniform setae on flexor proximal region.Dactylus of fourth and fifth pereopods with 2 or 3, rarely 1 or 4, spiniform setae on flexor margin.

Description. Rostrum ( Fig. 1A, B View Figure 1 ) slightly descending, falling short of distal margin of first article of antennular peduncle to reaching distal margin of second article; dorsal margin armed with 4–5 teeth, posteriormost tooth located at about rostral base; ventral margin with minute subapical tooth, rarely 2 teeth or toothless. Supraorbital tooth vestigial or absent.Antennal tooth present, acute.Pterygostomial margin angular, with 1 tooth.

Pleurae ( Fig. 1F View Figure 1 ) of pleonal segments 1–3 rounded posteroventrally; pleurae of pleonal segments 4–6 acute posteroventrally. Sixth segment 1.6 times as long as fifth; telson 1.1 times as long as sixth segment. Telson ( Fig. 1L View Figure 1 ) 2.5 times longer than proximal width, with 3 pairs of dorsolateral spiniform setae and posterior margin with 3 pairs of simple setae, intermediate pair longest and outer shortest.

Cornea generally wider and slightly shorter than eyestalk. First article of antennular peduncle with tooth on median region of ventral margin ( Fig. 1D View Figure 1 ); acute stylocerite of variable length from reaching distal margin of first article of antennular peduncle to distal margin of second article of antennular peduncle ( Fig.1C View Figure 1 ); stylocerite with tooth on proximal dorsolateral margin; second article of antennular peduncle with tooth on lateral margin with variable length from reaching half to slightly exceeding distal margin of third article of antennular peduncle; third article of antennular peduncle with triangular plate articulated on dorsodistal margin; inner flagellum overreaching outer flagellum; inner flagellum slender and elongate; outer f lagellum stout, with dense row of aesthetascs ( Fig. 1A View Figure 1 ). Antennal basicerite with 2 ventral teeth; carpocerite variable in length, not reaching or slightly exceeding half-length of scaphocerite; scaphocerite 2.5 times longer than median width, overreaching distal margin of third article of antennular peduncle, with tooth on lateral distal margin ( Fig. 1E View Figure 1 ); antennal f lagellum long, filiform, articulated slightly broader at base than tip.

Mandible asymmetrical ( Fig. 2A View Figure 2 ), molar process with serrated surface, incisor process with 5 teeth,palp absent. Maxillule ( Fig. 2B View Figure 2 ) with distally truncated and undivided endopod, with distal simple seta; endite with upper lacinia broad, with somewhat acute distomedial angle, with numerous plumose setae and 11 spiniform setae; lower lacinia slender, with numerous plumose setae distally. Maxilla ( Fig. 2C View Figure 2 ) with coxal endite distally truncated and bilobed basal endite slightly rounded, numerous plumose setae on both endites; short endopod, distally slender, with plumose setae; exopod (scaphognathite) welldeveloped, rounded, truncated terminal margin, with numerous plumose setae.

First maxilliped ( Fig. 2D View Figure 2 ) with coxal and basal endites similar in length,covered by numerous plumose setae; both endites with distal margin slightly rounded; undivided endopod, with plumose setae; exopod well developed and undivided, with some plumose setae on proximal region and numerous plumose setae on distal region; proximal and distal lobes of large epipod similar in width.Second maxilliped( Fig.2E View Figure 2 )with protopodite with plumose setae; endopod with 4 articles, merus 3.1 times as long as dactylus, carpus 3 times as long as dactylus, propodus 10 times as long as dactylus, propodus and dactylus with numerous plumose setae; long, slender, undivided exopod, some plumose setae on proximal region and numerous plumose setae on distal region.Third maxilliped ( Fig. 2G View Figure 2 )overreaching antennular peduncle; antepenultimate article 0.9 times as long as ultimate article, with some plumose setae, distal region unarmed or with 1 papillose seta ( Fig. 2F View Figure 2 ) and 0 or 1 spiniform seta, with variable positions; penultimate article 0.3 times as long as ultimate article, with some simple and plumose setae; ultimate article with many simple and plumose setae, tip with 7 or 8 spiniform setae; exopod not reaching distal margin of antepenultimate article, with tuft of plumose setae on tip.

Pereopods without epipods. First pereopod ( Fig. 1G View Figure 1 ) of variable length, not reaching or exceeding half-length of scaphocerite; ischium, merus, carpus, and propodus 2.0, 3.2, 2.8, 3.9 times as long as basis, respectively; ischium with 1 spiniform seta on distal flexor region; merus with 1 or 2, rarely3 or 4, spiniform setae on f lexor proximal region; chela slender, fingers 0.6 times as long as palm, both with short setae on cutting edge and tufts of setae on lateral edge. Second pereopod ( Fig. 1H View Figure 1 ) with ischium, merus, carpus, and propodus 4.3, 4.6, 7.2, 2.6 times as long as basis, respectively; ischium with 2 simple and long setae on proximal flexor region; carpus subdivided into 6 articles, length ratio of carpal articles from proximal to distal 2:1:4:3:2.5:3; chela slender, fingers 0.7 times as long as palm, both with tufts of setae on lateral margin.Third pereopod ( Fig.1I View Figure 1 ) with ischium, merus, carpus, and propodus 2.2, 4.3, 2.1, 5.1 times as long as basis, respectively; merus with 1 to 3 lateral spiniform seta on distal region; carpus with tip of dorsal region projected anteriorly; flexor region of propodus with 7 to 16 spiniform setae, distal setae paired; male specimen (UF 44289) with tuft of setae on distal region of f lexor margin; dactylus 0.2 times as long as propodus, distally biunguiculate with 2 or 3, rarely 4, spiniform setae on flexor margin. Fourth pereopod ( Fig. 1J View Figure 1 ) with ischium, merus, carpus, and propodus 2.3, 4.9, 2.5, 5.7 times as long as basis, respectively; merus with 1 spiniform seta on distal region, tuft of setae on distal dorsal region; carpus with tip of dorsal region projected anteriorly; flexor region of propodus with 8 to 12 spiniform setae, distal setae paired; dactylus 0.2 times as long as propodus, distally biunguiculate with 2 or 3 spiniform setae on flexor margin. Fifth pereopod ( Fig.1K View Figure 1 ) with ischium, merus, carpus, and propodus 2.2, 4.2, 2.2, 5.4 times as long as basis, respectively; merus unarmed (rarely) or with 1 spiniform seta on distal region, tuft of setae on distal dorsal region; carpus with tip of dorsal region projected anteriorly; flexor region of propodus with 8 to 15 spiniform setae, distal setae paired, some specimens with tuft of simple setae on distal region of flexor margin; dactylus 0.2 times as long as propodus, distally biunguiculate with 2 or 3, rarely 1, spiniform setae on flexor margin.

Exopod of uropod 1.1 times as long as endopod ( Fig.1L View Figure 1 ); exopod with distolateral tooth and spiniform setae between distolateral tooth and margin of blade.

Type locality. Panama, Bocas del Toro, Isla Cristóbal ,

NW side, “Seagal”.

Distribution. Western Atlantic — Panama (this study).

Variations. One male paratype (UF 44289, 1.9 mm CL) presented a tuft of setae on the distal region of the flexor margin of the propodus of the third pereopod. This tuft was absent in the other male paratype examined (UF 44518, 2.2 mm CL).