A new species of Litarachna Walter, 1925 (Acari: Hydrachnidia: Pontarachnidae) from Corozal Bay (Belize), described based upon morphology and DNA barcodes Author Montes-Ortiz, Lucia El Colegio de la Frontera Sur, Avenida Centenario km 5.5, Chetumal 77014, Quintana Roo, México. Author Goldschmidt, Tom Zoologische Staatssammlung München, Münchhausenstrasse 21, D- 81247 München, Germany. Author Vásquez-Yeomans, Lourdes El Colegio de la Frontera Sur, Avenida Centenario km 5.5, Chetumal 77014, Quintana Roo, México. Author Elías-Gutiérrez, Manuel El Colegio de la Frontera Sur, Avenida Centenario km 5.5, Chetumal 77014, Quintana Roo, México. text Acarologia 2021 2021-07-21 1925 3 602 613 journal article 2107-7207 Litarachna belicensis n. sp. Zoobank: A09F5614-209C-4446-A6F6-5BE541E56D97 ( Figures 2–6 ) Type series — Holotype : female, Corozal Bay , Belize (18°37´27.7 ´´ N 88°28 ´8.44 ´´ W), 3-5 m depth, substrate mainly calcareous rocks and sand, also sea grass and some spots of fuzzy finger algae Batophora ( oerstedi ), collection from a planktonic sample from 2.8 m depth, 7 May 2019 ; dissected and slide mounted in glycerin jelly. Paratypes : one male , same collecting data and processing as holotype . Diagnosis — Suture between Cx-II and Cx-III incomplete, suture between Cx-III and Cx-IV complete ( Figure 6A and D ). Postero-medial apodemes twice length of postero-lateral apodemes in both female and male. Ventral projection in P-2 ( Figure 3B and 5B ), in male very long perigenital setae surrounding the genital field, U-shaped ( Figure 5A ). Description — Female (n=1): Idiosoma L/W 476/357. Anterior coxal group separated medially. Suture lines between Cx-II and Cx-III incomplete. Suture lines between Cx-I and Cx-II, and complete between Cx-III and Cx-IV. Posterior margin of Cx-IV with two pairs of long apodemes, extending beyond the genital field, postero-lateral apodemes half as long as postero-medial apodemes ( Figures 2 , 3 , 6 A-C) Genital field L/W 78/47. Pregenital and postgenital sclerite fused, forming a ring around genital opening. Cxgl-2 and associated seta sensu (Cook 1974) lie between genital field and the fourth coxae. Posterior to the genital field, a lateral pair of Vgl, and three pairs of wheel-like acetabula ( sensu Cook 1996 ), W-1 with nine radiating spokes, W-2 with eight and seven radiating spokes and W-3 with 10 radiating spokes ( Figures 3 and 4 ). A pair of platelets bearing two pores latero-anteriorly to the excretory pore. Excretory pore sclerotized in subterminal position. Palp ( Figure 3C ) total L 194, dorsal L (% of total L): P-1 27 (14%), P-2 33 (17%), P-3 40 (20%), P-4 71 (36%), P-5 25 (13%), P-2 bearing a ventral projection ( Figure 3B ). L of I-Leg- 3-6: 34, 51, 60, 85; II-Leg-3-6: 40, 51, 88, 91; III-Leg-3-6: 28, 52, 95, 85 and IV-Leg-3-6: 57, 95, 119, 104, Leg III and Leg IV each with one swimming seta ( Figure 3 ). One ovigerous female from the material contained two eggs with a L/W 170/110 ( Figure 8 ). Male (n=1): Idiosoma L/W 400/348. First coxal plates fused as in the female, suture lines between Cx-II and Cx-III medially incomplete, suture lines complete between Cx-I and Cx-II, as well as between Cx-III and Cx-IV. Postero-medial apodemes twice as long as postero-lateral apodemes, reaching to posterior end of genital field ( Figure 6D ). Between posterior and lateral apodemes Cxgl-4. Genital field L/W 35/28, genital sclerites forming a complete ring with four pairs of setae ( Figure 5C ), many long perigenital setae (>95) free in the integument surrounding the genital field in a U-shaped form with less dense cover of setae anteriorly and markedly increasing density towards posterior part ( Figure 5B ); one pair of tiny, wheel-like acetabula at center of perigenital setae, close to the genital opening ( Figure 5C ). Genital opening flanked by centrally extended lamellae, posterior to the genital field two pores and two pairs of wheel-like acetabula ( sensu Cook 1996 ), W-1, W-3 with nine radiating spokes, W-2 with six and four radiating spokes ( Figure 5 ). Figure 2 Litarachna belicensis n. sp . Female: A - Dorsal view; B - ventral view. Male: C - Dorsal view; D - Ventral view. Scalebar = 100 μm. Palp ( Figure 5A - B ) total L 186, dorsal L (% of total L): P-1 28 (15%), P-2 38 (21%), P-3 40 (22%), P-4 57 (31%), P-5 22 (11%), P-2 bearing a ventral projection ( Figure 5B ). L Figure 3 SEM micrographs of Litarachna belicensis n. sp. Female: A - Habitus (W-1 wheel acetabula, W-2, W-3); B - palps (arrows point at ventral processes on P-2); C - genital field. Figure 4 SEM micrographs of wheel acetabula in female of Litarachna belicensis n. sp. B, C – wheel acetabula 1; A, D – wheel acetabula 2. Scalebar = 5 µm of I-Leg-3-6: 39, 50, 64, 54; II-Leg-3-6: 39, 50, 64, 54; III-Leg-3-6: 39, 53, 92, 89 and IV-Leg-3-6: 46, 89, 100, 100. DNA sequence (CO1) — Two sequences were obtained and resulted in the following consensus sequence: CTCTATTTTG CTTTAGGAAG ATGATCAGGC ATAATGGGAA CAAGACTTAG 50 AACTTTAATT CGATTAGAAT TAGGTCAACC AGGAGCACTA ATTGGCAATG 100 AACAAATCTA TAACGTTATC GTAACAGCTC ATGCATTTAT TATAATTTTT 150 TTCATAGTCA TACCCATAAT AATTGGAGGT TTTGGAAATT GATTAGTTCC 200 GCTAATAATC AGAGCCCCCG ATATAGCCTT TCCCCGTATA AATAACATAA 250 GATTCTGACT TTTACCCCCA GCCCTTATCC TTCTTTCAAC AAGATCCATA 300 AGATCAATAG GAGCTGGTAC AGGCTGAACA GTTTACCCTC CCCTCTCAAG 350 AAATTTGGCT CACTCAGGAC CATCCGTTGA CTTAACAATC TTCTCTCTCC 400 ATTTAGCTGG TATTTCATCC ATCCTTGGGG CCATCAACTT TATAGCAACA 450 ATTATAAATA TAAAACCTAC CCATATAAAA ATGGAACAAG TACCCCTATT 500 TGTATGATCA ATTTTCATCA CAACCATTCT CCTCCTTCTT TCACTTCCAG 550 TCTTAGCAGG AGCCATTACT ATGCTTTTAA CTGACCGAAA CTTCAACACT 600 TCATTCTTTG ATCCAGCCGG TGGAGGTGAT CCAATTTTAT ACCAACATTT 650 Etymology — This species is named for the country where it was collected.