Otacilia haitun sp. nov.

(Figs 8−11, 21)

Type material. China, Guangxi Zhuang Autonomous Region, Nanning City, Damingshan National Natural Reserve. Holotype: ♁: Shanglin County, Yongjun Station, 23°27'19.15"N, 108°29'36.63"E, 518 m, 8.11.2018 . Paratypes: 1 ♀, with same data as holotype; 1 ♁, 1 ♀, Shanglin County, Xiyan Station, Shuiyuan Village, 23°24'39.88"N, 108°31'48.33"E, 517 m, 9.11.2018 ; 1 ♀, Shanglin County, Xiyan Station, Yongjun, 23°27'43.14"N, 108°30'13.47"E, 517 m, 8.11.2018 ; 1 ♁, Shanglin County, Sanbao Station, Chaoyang, 23°31'36.48"N, 108°21'4.2"E, 604 m, 3.11.2018 ; 6 ♁, 3 ♀, 23°31'26.04"N, 108°22'11.64"E, 915 m, 2.11.2018, other data as previous; 2 ♀, same data as previous; 3 ♁, 2 ♀, 23°31'13.67"N, 108°23'4.56"E, 593 m, other data as previous; 6 ♁, 12 ♀, Wuming County, Daxiagu (meaning grand canyon), 23°29'57.48"N, 108°25'43.67"E, 914 m, 1.11.2018 ; 2 ♁, 2 ♀, Shanglin County, Jilong Station, 23°26'5.27"N, 108°26'32.64"E, 591 m, 5.11.2018.

Etymology. The specific epithet comes from the Chinese pinyin 'haitun' meaning 'dolphin', which refers to the shape of the retrolateral tibial apophysis (in dorsal view) resembling a dolphin; noun in apposition.

Diagnosis. The male of this species is similar to that of O. yinae Liu, Xu, Xiao, Yin & Peng, 2019 (Liu et al. 2022: sppl. 2: 78, figs 138k, 139k, 140k) in having a V-shaped sperm duct (SD), a triangular retrolateral tegular apophysis (rTA) and a short, curved embolus (E) as long as retrolateral tegular apophysis, but differs by the retrolateral tibial apophysis (RTA) with a dolphin-shaped part anteriorly and a small triangular branch basally (Figs 8 D−F, 10A−C, 11C, D) (vs. two spine-like parts). The female of this species can be distinguished from those of other Otacilia species by the copulatory ducts and spermathecae (SP) close to each other (Figs 9D, 10E) (vs. separated, either one of them or both).

Description: Male (holotype). Habitus as in Figs 8A, B. Total length 3.40, carapace 1.76 long, 1.53 wide. Eye sizes and interdistances: AME 0.09, ALE 0.11, PME 0.09, PLE 0.09; interdistances: AME−AME 0.05, ALE−AME 0.03, PME−PME 0.12, ALE−ALE 0.27, PLE−PME 0.06, PLE−PLE 0.40, ALE−PLE 0.11, AME−PME 0.11, AME−PLE 0.18. MOA 0.30 long, anterior width 0.21, posterior width 0.3. Chelicera with3 promarginal (proximal one largest, distal one smallest) and 5 retromarginal teeth (distal one largest, proximal one smallest). Sternum longer than wide, posteriorly pointed. Abdomen1.84 long, 1.07 wide, with large dorsal scutum extending beyond anterior half of abdomen. Legs measurements: I 8.30 (2.08, 0.68, 2.63, 2.00, 0.91); II 6.35 (1.64, 0.59, 1.88, 1.46, 0.78); III 5.00 (1.27, 0.52, 1.05, 1.41, 0.75); IV 7.94 (2.04, 0.60, 2.00, 2.25, 1.05). Legs spination: femora I−IV with one dorsal spine; femora I pv11111, II pv1111; tibiae I v22222222, II v2222222; metatarsi I v2222, II pv2222, rv1111.

Colouration (Figs 8A, B). Carapace yellow-brown, with radial, irregular dark grey mottled markings. Cervical groove and fovea distinct. Chelicerae, endites, labium and sternum yellow-brown. Abdomen dark brown, with oval white stripes in front of the anal tubercle; venter grey to yellow, with two distinct dark brown stripes between epigastric groove and anterior spinnerets. Leg femora dark brown, other segments yellow.

Palp (Figs 8 C−F, 10A−C, 11). Femoral apophysis (FA) weakly sclerotized, nearly as long as 1/3 of femur. Retrolateral tibial apophysis (RTA) dolphin-shaped in dorsal view, large, strong, slightly longer than tibia, with a triangular branch at its base in dorsolateral view. Sperm duct (SD) nearly V-shaped in ventral view, sclerotized, extended from base of retrolateral tegular apophysis to embolic base, reaching beyond the middle part of tegulum. Retrolateral tegular apophysis (rTA) strongly sclerotized, triangular, longer than embolus, antero-laterally located. Embolus (E) short, slightly curved, arising at about 12 o’clock position.

Female. Habitus as in Figs 9A, B. As in male except as noted. Total length 4.08, carapace 1.80 long, 1.66 wide. Eye sizes and interdistances: AME 0.10, ALE 0.10, PME 0.10, PLE 0.10; interdistances: AME−AME 0.06, ALE−AME 0.03 PME−PME 0.12, ALE−ALE 0.30, PLE−PME 0.07, PLE−PLE0.45, ALE−PLE 0.11, AME−PME 0.09, AME−PLE 0.19. MOA 0.27 long, anterior width 0.24, posterior width 0.32. Abdomen 2.14 long, 1.30 wide, without dorsal scutum. Labium wider than long. Legsmeasurements: I 7.60 (2.00, 0.69, 2.41, 1.85, 0.65); II 5.90 (1.60, 0.55, 1.84, 1.13, 0.78); III 4.72 (1.36, 0.50, 1.00, 1.28, 0.58); IV 7.36 (1.86, 0.64, 2.00, 2.06, 0.80). Legs spination: femur II pv111; tibiae I v2222222, II v2222222.

Colouration (Fig. 9A, B). Lighter than males. Abdomen dark brown, with four faint chevrons posteriorly.

Epigyne (Figs 9C, D, 10D, E). Epigynal plate I-shaped, longer than wide. Copulatory ducts, connecting tubes and spermathecae distinctly visible through integument. Copulatory openings (CO) oval, located anterolaterally, with arc-shaped sclerotized margin. Copulatory ducts (CD) very short, shorter than connecting tubes, with a sharp turn. Glandular appendage (GA) very short, directed laterally. Connecting tubes (CT) with a sharp turn, posterior parts touching and slightly widened. Spermathecae (SP) ovoid, contiguous, located subposteromedially. Fertilization duct (FD) long, slightly shorter than spermatheca, located apically on spermathecae, directed anterolaterally.

Distribution. Known only from the type locality in Guangxi Zhuang Autonomous Region, China (Fig. 21).