Resolution of the Acroteriobatus leucospilus species complex, with a redescription of A. leucospilus (Norman, 1926) and descriptions of two new western Indian Ocean species of Acroteriobatus (Rhinopristiformes, Rhinobatidae) Author Weigmann, Simon Elasmo-Lab, Elasmobranch Research Laboratory, Georg-Bonne-Str. 5 83, 22609 Hamburg, Germany & Center of Natural History, University of Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany simon.weigmann@elasmo-lab.de & simon.weigmann@unihamburg.de Author Ebert, David A. Pacific Shark Research Center, Moss Landing Marine Laboratories, Moss Landing, CA 95039, USA & South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown 6140, South Africa & Department of Ichthyology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA Author Séret, Bernard IchtyoConsult, 6 bis rue du Centre, 91430, Igny, France text Marine Biodiversity 2021 2021-06-21 51 1 30 journal article 10.1007/s12526-021-01208-6 54629b9a-8031-4e3b-bae4-79622c6be2a2 5825445 A2D68C03-7D2A-4F8F-82B2-A06CB6A8A2C1 Genus Acroteriobatus Giltay, 1928 Type species: Rhinobatus (Syrrhina) annulatus Smith in Müller & Henle, 1841 by subsequent designation Fig. 1 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 565 mm TL fresh, in total dorsal view taken directly after catching. Photograph by Elaine Heemstra, NRF-SAIAB Fig. 3 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 550 mm TL, in total ventral view. Scale bar: 5 cm. Photograph courtesy Marsha Englebrecht © Fig. 4 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 565 mm TL fresh, head in dorsal view taken directly after catching. Photograph by Elaine Heemstra, NRF-SAIAB Fig. 6 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 550 mm TL, close-up of orbital and spiracular region. Photograph courtesy Marsha Englebrecht © Fig. 5 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 550 mm TL, head in dorsal view. Photograph courtesy Marsha Englebrecht © Fig. 7 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 565 mm TL fresh, head in ventral view taken directly after catching. Photograph by Elaine Heemstra, NRF-SAIAB Fig. 8 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 550 mm TL, head in ventral view. Photograph courtesy Marsha Englebrecht © Fig. 10 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 550 mm TL; first dorsal ( a ), second dorsal ( b ), and caudal ( c ) fins in lateral views ( c image reversed). Photographs courtesy Marsha Englebrecht © Fig. 9 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 550 mm TL, close-up of mouth-nasal region. Photograph courtesy Marsha Englebrecht © Fig. 11 Acroteriobatus andysabini sp. nov. , SAIAB 97396, juvenile male holotype, 550 mm TL, radiograph of cranium and snout in dorsal view. The radiograph was taken and kindly provided by Jon Fong Fig. 12 Acroteriobatus andysabini sp. nov. , Malagasy artisanal fisherman with large (~1000 mm TL) specimen. The photograph was taken and kindly provided by Kerry Sink Fig. 13 Map of the southwestern Indian Ocean depicting the catch locations of the examined specimens of all three species of the Acroteriobatus leucospilus species complex. Holotype (white star) and paratypes (white circles) of A. andysabini sp. nov. , holotype (gray star) and paratypes (gray star and gray circle) of A. stehmanni sp. nov. , and syntypes (black triangles) and other specimens (black squares) of A. leucospilus Table 1 Acroteriobatus andysabini sp. nov. , morphometrics and meristics
Acroteriobatus andysabini sp. nov. , juvenile male holotype, SAIAB 97396 Acroteriobatus andysabini sp. nov. , juvenile female paratype, SAIAB 189815 Minimum ( n = 9) Maximum ( n = 9) Mean ( n = 11) SD
mm % TL mm % TL % TL % TL % TL
Total length (mm) 550.0 100.0 345.0 100.0 178.0 603.0 351.2
Disc width, max 187.0 34.0 117.0 33.9 32.8 39.3 35.7 2.4
Disc length, direct/point-to-point (ptp) 228.0 41.5 145.0 42.0 38.1 45.1 42.3 2.2
Head length, dorsal (to occipital joint) 133.0 24.2 98.0 28.4 25.7 33.5 29.0 2.9
Head length, ventral (to 5th gill slit), ptp 139.0 25.3 93.0 27.0 25.0 29.8 27.3 1.8
Snout length, presocket 69.0 12.5 44.0 12.8 11.4 15.2 13.4 1.2
Orbit diameter, ptp 17.0 3.1 12.0 3.5 3.2 5.2 4.0 0.7
Spiracle length 10.0 1.8 7.0 2.0 1.8 3.7 2.4 0.6
Orbit and spiracle length 27.0 4.9 18.0 5.2 4.7 7.4 6.0 1.1
Interorbital width 1 (skeletal) 19.0 3.5 13.0 3.8 3.7 4.7 4.0 0.4
Interspiracular width 29.0 5.3 19.0 5.5 4.8 7.3 6.0 0.9
Preoral length 83.0 15.1 53.0 15.4 14.3 17.8 16.0 1.3
MOW, mouth width 34.0 6.2 21.0 6.1 6.0 8.4 6.8 0.9
Prenarial length, ptp 67.0 12.2 42.0 12.2 11.3 14.1 12.6 1.0
NOW, nostril length 22.0 4.0 13.0 3.8 3.0 4.7 4.0 0.5
AAW, anterior nasal aperture, width 7.0 1.3 5.0 1.4 1.0 1.7 1.3 0.2
ANF, anterior nasal flap, base length 18.0 3.3 12.0 3.5 2.8 4.1 3.4 0.5
ANW, anterior nasal flap, width 10.0 1.8 7.0 2.0 1.4 2.5 1.8 0.3
PLT, posterolateral nasal flap, total length 10.0 1.8 8.0 2.3 1.6 3.6 2.5 0.6
PLW, posterolateral nasal flap, width 5.0 0.9 3.0 0.9 0.8 1.1 1.0 0.1
PNF, posterior nasal flap, base length 13.0 2.4 8.0 2.3 1.8 3.1 2.4 0.4
PNW, posterior nasal flap, width 7.0 1.3 3.0 0.9 1.0 1.4 1.1 0.2
INM, distance between lateral margins of anterior apertures 51.0 9.3 31.0 9.0 8.3 12.6 10.3 1.5
INW, distance between posterior margins of nostrils 17.0 3.1 11.0 3.2 3.0 4.5 3.7 0.6
INA, distance between insertions of anterior nasal flaps 7.0 1.3 5.0 1.4 0.7 2.6 1.3 0.6
Shortest direct distance from anterior opening of nostril to disc margin 29.0 5.3 21.0 6.1 4.9 7.7 6.1 0.9
Gill opening width, 3rd 8.0 1.5 5.0 1.4 1.4 2.2 1.7 0.3
Distance between first gill openings 65.0 11.8 43.0 12.5 11.4 14.6 12.9 1.2
Distance between fifth gill openings 44.0 8.0 29.0 8.4 7.3 10.7 9.1 1.2
Pelvic fin, length 96.0 17.5 59.0 17.1 15.2 16.6 16.3 0.6
Pelvic fin, anterior margin length 40.0 7.3 22.0 6.4 4.6 7.6 6.6 0.9
Pelvic fin, width 42.0 7.6 25.0 7.2 4.2 7.9 7.2 1.0
Pelvic fin, base length 62.0 11.3 34.0 9.9 7.2 11.4 9.9 1.2
Pelvic fin, inner margin length 34.0 6.2 28.0 8.1 6.2 8.7 7.2 0.9
First dorsal fin, length 39.0 7.1 23.0 6.7 5.9 7.1 6.7 0.4
First dorsal fin, anterior margin length 53.0 9.6 28.0 8.1 8.0 10.1 9.0 0.7
First dorsal fin, height 42.0 7.6 23.0 6.7 4.6 7.4 6.6 0.9
First dorsal fin, base length 28.0 5.1 15.0 4.3 3.8 4.7 4.3 0.4
First dorsal fin, inner margin length 13.0 2.4 6.0 1.7 2.3 3.4 2.7 0.5
Second dorsal fin, length 40.0 7.3 25.0 7.2 6.1 7.9 7.2 0.5
Second dorsal fin, anterior margin length 52.0 9.5 29.0 8.4 8.5 9.8 9.1 0.4
Second dorsal fin, height 40.0 7.3 21.0 6.1 5.5 7.9 6.5 0.8
Second dorsal fin, base length 25.0 4.5 17.0 4.9 3.9 5.2 4.7 0.4
Second dorsal fin, inner margin length 17.0 3.1 8.0 2.3 2.0 3.4 2.8 0.5
Table 1 (continued)
Acroteriobatus Acroteriobatus Minimum Maximum Mean SD
andysabini sp. nov. , juvenile male holotype, SAIAB 97396 andysabini sp. nov. , juvenile female paratype, SAIAB 189815 ( n = 9) ( n = 9) ( n = 11)
mm % TL mm % TL % TL % TL % TL
Caudal fin, dorsal margin 72.0 13.1 50.0 14.5 13.1 15.4 14.3 0.7
Caudal fin, preventral margin 45.0 8.2 29.0 8.4 6.3 9.5 8.0 1.1
Snout to pelvic-fin origin ptp 198.0 36.0 132.0 38.3 34.5 40.8 38.1 2.0
Snout to anterior vent 223.0 40.5 141.0 40.9 35.6 43.6 40.9 2.5
Snout to first dorsal-fin origin 330.0 60.0 205.0 59.4 58.4 61.5 59.7 0.9
Snout to second dorsal-fin origin 413.0 75.1 257.0 74.5 73.5 76.3 74.4 0.9
Snout to upper caudal-fin origin 472.0 85.8 295.0 85.5 83.1 86.7 85.2 1.1
Snout to lower caudal-fin origin 470.0 85.5 303.0 87.8 84.6 88.2 86.8 1.1
Pelvic-fin insertion to dorsal-fin origin 76.0 13.8 42.0 12.2 9.6 13.9 11.8 1.5
Interdorsal distance 59.0 10.7 38.0 11.0 7.1 11.6 10.2 1.3
Disc width, anterior orbit 114.0 20.7 75.0 21.7 19.1 26.2 22.8 2.4
Body width, pelvic insertion 55.0 10.0 38.0 11.0 9.0 14.1 11.1 1.6
Body width, first dorsal-fin origin 53.0 9.6 35.0 10.1 8.4 10.8 9.5 0.8
Body width, second dorsal-fin origin 29.0 5.3 19.0 5.5 4.3 5.5 4.9 0.5
Body depth, maximum 29.0 5.3 18.0 5.2 4.5 5.7 5.1 0.3
Body depth, pelvic-fin insertion 25.0 4.5 15.0 4.3 3.4 5.0 4.3 0.5
Body depth, first dorsal-fin origin 22.0 4.0 13.0 3.8 3.0 4.1 3.6 0.4
Body depth, second dorsal-fin origin 13.0 2.4 8.0 2.3 2.0 2.7 2.3 0.2
Caudal peduncle length = dorsal (D2) - caudal space 37.0 6.7 21.0 6.1 5.1 8.4 6.8 0.9
Tail length from anterior vent 327.0 59.5 204.0 59.1 56.4 64.4 59.1 2.5
Angle before eyes, ° 79.1 80.9 76.0 84.6 80.5 2.4
Individual values forthe juvenile maleholotype (SAIAB 97396) and one female paratype (SAIAB 189815), ranges for allother SAIAB and CAS as well as the two larger MNHN paratypes ( n = 9), and means and standard deviations (SD) for all nine SAIAB and CAS as well as the two larger MNHN type specimens are presented. Proportional values are expressed as percentages of total length (TL) 70% ethanol preserved except for minimum, maximum, and mean of TL in mm Fig. 14 Acroteriobatus stehmanni sp. nov. , ZMH 25553, adult male holotype, 597 mm TL, in total dorsal view. Scale bar: 5 cm Fig. 15 Acroteriobatus stehmanni sp. nov. , ZMH 25553, adult male holotype, 597 mm TL, in total ventral view. Scale bar: 5 cm Fig. 16 Acroteriobatus stehmanni sp. nov. , ZMH 25557, adultfemale paratype, 602 mm TL fresh, in total dorsal view taken directly after catching.Scale bar: 5 cm. The photograph was taken and kindly provided by Matthias Stehmann Fig. 17 Acroteriobatus stehmanni sp. nov. , ZMH 25558, adultfemale paratype, 594 mm TL fresh, in total dorsal view taken directly after catching.Scale bar: 5 cm. The photograph was taken and kindly provided by Matthias Stehmann Fig. 18 Acroteriobatus stehmanni sp. nov. , ZMH 25560, juvenile male paratype, 201.4 mm TL, in total dorsal view. Scale bar: 5 cm Fig. 19 Acroteriobatus stehmanni sp. nov. , ZMH 25553, adult male holotype, 597 mm TL, head in dorsal view. Scale bar: 5 cm Fig. 21 Acroteriobatus stehmanni sp. nov. , ZMH 25553, adultmale holotype, 597 mm TL, head in ventral view. Scale bar: 5 cm Fig. 20 Acroteriobatus stehmanni sp. nov. , ZMH 25553, adult male holotype, 597 mm TL, close-up of orbital and spiracular region. Scale bar: 2 cm Fig. 22 Acroteriobatus stehmanni sp. nov. , ZMH 25553, adultmale holotype, 597 mm TL, close-up of mouth-nasal region. Scale bar: 2 cm Fig. 23 Acroteriobatus stehmanni sp. nov. , ZMH 25553, adult male holotype, 597 mm TL; first dorsal ( a ), second dorsal ( b ), and caudal ( c ) fins in lateral views. Scale bar: 2 cm Fig. 24 Acroteriobatus stehmanni sp. nov. , enlarged dermal denticles of a–e adultmale holotype, ZMH 25553, 597 mm TL, and f–i smallest juvenile paratype, ZMH 25560, male, 201.4 mm TL. a , b preorbital denticles in a overview and b close-up view; c postorbital denticle; d spiracular denticles; e midline denticles; f preorbital denticles; g postorbital denticles; h spiracular denticle; i midline denticles. Scale bars: a 2 mm and b–i 1 mm Fig. 25 Acroteriobatus stehmanni sp. nov. , row of enlarged dermal denticles along midline from nape to first dorsal-fin origin of a adult male holotype, ZMH 25553, 597 mm TL, and b smallest juvenile paratype, ZMH 25560, male, 201.4 mm TL. Scale bars: a 5 cm and b 2 cm Fig. 26 Acroteriobatus stehmanni sp. nov. , ZMH 25553, adultmale holotype, 597 mm TL, radiograph of cranium and snout in dorsal view Fig. 27 Acroteriobatus stehmanni sp. nov. , ZMH 25560, juvenile male paratype, 201.4 mm TL, head in ventral view. Scale bar: 2 cm Table 2 Acroteriobatus stehmanni sp. nov. , morphometrics and meristics
Acroteriobatus stehmanni sp. nov. , adult male holotype, ZMH 25553 Acroteriobatus stehmanni sp. nov. , adult female paratype, ZMH 25557 Minimum ( n = 6) Maximum ( n = 6) Mean ( n = 8) SD
mm % TLmm % TL % TL % TL % TL
Total length (mm) 597.0 100.0 603.0 100.0 201.4 613.0 511.3
Disc width, max 175.0 29.3 190.2 31.5 28.5 35.9 30.9 2.5
Disc length, direct/point-to-point (ptp) 228.0 38.2 241.3 40.0 37.6 45.2 39.7 2.5
Head length, dorsal (to occipital joint) 106.0 17.8 108.1 17.9 17.2 22.8 18.5 1.8
Head length, ventral (to 5th gill slit), ptp 145.5 24.4 144.0 23.9 23.6 29.7 25.1 2.0
Head length, ventral (to 5th gill slit), horizontal 143.9 24.1 142.3 23.6 23.2 29.4 24.8 2.0
Snout length, direct (pre-eyeball) 80.4 13.5 78.9 13.1 13.1 17.3 14.0 1.4
Snout length, horizontal (pre-eyeball) 78.6 13.2 76.3 12.6 12.7 16.5 13.6 1.2
Snout length, presocket 77.6 13.0 75.5 12.5 12.2 16.3 13.4 1.2
Orbit diameter, ptp 20.6 3.5 22.0 3.6 3.3 4.6 3.7 0.4
Spiracle length 11.5 1.9 11.9 2.0 1.6 2.5 2.0 0.2
Orbit and spiracle length 26.9 4.5 28.1 4.7 4.1 5.7 4.6 0.5
Interorbital width 1 (skeletal) 17.9 3.0 17.9 3.0 3.1 4.1 3.3 0.4
Interorbital width 2 (= intereye width) 37.2 6.2 37.1 6.2 5.9 8.6 6.6 0.9
Interspiracular width 27.9 4.7 28.1 4.7 4.5 6.3 5.0 0.6
Preoral length 94.7 15.9 90.2 15.0 14.9 19.2 16.0 1.4
MOW, mouth width 32.2 5.4 32.1 5.3 5.2 6.7 5.6 0.5
Prenarial length, ptp 73.1 12.2 71.7 11.9 11.7 15.6 12.7 1.3
NOW, nostril length 20.5 3.4 18.1 3.0 3.0 3.4 3.2 0.2
AAW, anterior nasal aperture, width 6.1 1.0 6.6 1.1 1.0 1.2 1.1 0.1
ANF, anterior nasal flap, base length 17.8 3.0 16.9 2.8 2.8 3.8 3.0 0.3
ANW, anterior nasal flap, width 9.5 1.6 9.2 1.5 1.5 1.7 1.6 0.1
PLT, posterolateral nasal flap, total length 16.8 2.8 15.2 2.5 2.6 2.8 2.7 0.1
PLF, posterolateral nasal-flap anterior exposed base length 7.1 1.2 7.3 1.2 1.1 1.9 1.3 0.2
PLW, posterolateral nasal flap, width 4.3 0.7 4.3 0.7 0.6 1.1 0.8 0.2
PNF, posterior nasal flap, base length 11.7 2.0 10.7 1.8 1.9 2.1 1.9 0.1
PNW, posterior nasal flap, width 5.4 0.9 5.1 0.9 0.8 1.1 0.9 0.1
INM, distance between lateral margins of anterior apertures 49.4 8.3 49.3 8.2 8.3 9.8 8.6 0.5
INW, distance between posterior margins of nostrils 13.7 2.3 14.8 2.5 2.3 3.5 2.6 0.4
INA, distance between insertions of anterior nasal flaps 6.0 1.0 5.6 0.9 0.8 1.1 1.0 0.1
Shortest direct distance from anterior opening of nostril to disc margin 20.3 3.4 23.9 4.0 3.5 5.7 4.0 0.8
Gill opening width, 1st 7.7 1.3 7.5 1.2 1.0 1.4 1.3 0.1
Gill opening width, 2nd 7.7 1.3 8.1 1.3 1.1 1.5 1.3 0.1
Gill opening width, 3rd 7.7 1.3 8.4 1.4 1.2 1.7 1.3 0.2
Gill opening width, 4th 7.4 1.2 7.9 1.3 1.2 1.5 1.3 0.1
Gill opening width, 5th 5.2 0.9 6.1 1.0 0.9 1.1 1.0 0.1
Distance between first gill openings 64.9 10.9 71.1 11.8 10.9 14.5 11.8 1.2
Distance between fifth gill openings 45.9 7.7 51.2 8.5 7.5 9.8 8.2 0.8
Pelvic fin, length 99.1 16.6 108.8 18.0 15.8 17.6 16.8 0.7
Pelvic fin, anterior margin length 55.0 9.2 58.8 9.8 8.5 10.0 9.4 0.5
Pelvic fin, width 33.8 5.7 43.2 7.2 4.9 6.9 6.0 0.8
Pelvic fin, base length 53.1 8.9 69.8 11.6 7.2 11.1 9.5 1.3
Pelvic fin, inner margin length 53.1 8.9 47.6 7.9 7.9 8.9 8.5 0.5
First dorsal fin, length 39.2 6.6 38.3 6.3 6.3 6.9 6.6 0.2
Table 2 (continued)
Acroteriobatus Acroteriobatus Minimum Maximum Mean SD
stehmanni sp. stehmanni sp. ( n = 6) ( n = 6) ( n = 8)
nov., adult male holotype, ZMH 25553 nov., adult female paratype, ZMH 25557
mm % TL mm % TL % TL % TL % TL
First dorsal fin, anterior margin length 53.6 9.0 55.0 9.1 8.8 10.0 9.2 0.4
First dorsal fin, height 39.2 6.6 42.3 7.0 5.8 7.6 6.7 0.5
First dorsal fin, base length 29.2 4.9 25.2 4.2 4.2 5.0 4.6 0.3
First dorsal fin, inner margin length 10.6 1.8 11.6 1.9 1.7 2.6 2.0 0.3
Second dorsal fin, length 40.4 6.8 39.0 6.5 6.4 7.1 6.7 0.2
Second dorsal fin, anterior margin length 49.5 8.3 52.8 8.8 8.3 9.9 8.8 0.5
Second dorsal fin, height 36.1 6.1 38.9 6.4 5.9 7.0 6.3 0.4
Second dorsal fin, base length 31.1 5.2 28.7 4.8 4.6 5.3 5.0 0.2
Second dorsal fin, inner margin length 10.2 1.7 10.8 1.8 1.5 2.3 1.8 0.3
Caudal fin, dorsal margin 71.5 12.0 69.2 11.5 10.9 14.6 12.0 1.1
Caudal fin, preventral margin 47.7 8.0 42.1 7.0 7.0 8.4 7.7 0.5
Snout to pelvic-fin origin ptp 207.2 34.7 215.7 35.8 32.9 40.7 35.5 2.4
Snout to anterior vent 228.7 38.3 241.2 40.0 37.1 43.8 39.4 2.2
Snout to first dorsal-fin origin 353.0 59.1 370.0 61.4 58.4 61.8 60.0 1.3
Snout to second dorsal-fin origin 455.0 76.2 462.0 76.6 75.0 77.5 76.4 0.7
Snout to upper caudal-fin origin 525.0 87.9 530.0 87.9 86.4 88.8 87.7 0.8
Snout to lower caudal-fin origin 530.0 88.8 533.0 88.4 86.2 89.1 88.3 1.0
Pelvic-fin insertion to dorsal-fin origin 96.1 16.1 89.2 14.8 13.0 16.2 15.1 1.2
Interdorsal distance 74.2 12.4 68.6 11.4 10.8 13.1 12.0 0.8
Disc width, anterior orbit 103.5 17.3 103.5 17.2 16.7 22.9 18.2 2.0
Body width, pelvic insertion 58.1 9.7 59.7 9.9 8.2 10.9 9.9 0.7
Body width, first dorsal-fin origin 55.4 9.3 59.0 9.8 7.5 10.4 9.5 0.9
Body width, second dorsal-fin origin 31.1 5.2 32.9 5.4 4.5 5.7 5.3 0.4
Body depth, anterior orbit 18.4 3.1 20.5 3.4 3.0 3.8 3.3 0.3
Body depth, maximum 25.7 4.3 27.5 4.6 4.2 5.3 4.7 0.4
Body depth, pelvic-fin insertion 25.4 4.3 26.7 4.4 3.7 4.8 4.4 0.4
Body depth, first dorsal-fin origin 21.0 3.5 21.3 3.5 2.9 3.8 3.5 0.3
Body depth, second dorsal-fin origin 14.2 2.4 14.7 2.4 2.1 2.5 2.4 0.1
Body depth, caudal peduncle 9.0 1.5 10.2 1.7 1.5 1.6 1.6 0.1
Caudal peduncle length = dorsal (D2) - caudal space 40.0 6.7 39.6 6.6 6.1 6.9 6.5 0.3
Tail length from anterior vent 368.3 61.7 361.8 60.0 56.2 62.9 60.6 2.2
Angle before eyes, ° 72.0 77.0 71.0 75.0 73.0 2.0
Individual values for the adult male holotype (ZMH 25553) and one adult female paratype (ZMH 25557), ranges for all other ZMH paratypes ( n = 6), as well as means and standard deviations (SD) for all eight ZMH type specimens are presented. Proportional values are expressed as percentages of total length (TL) 70% ethanol preserved except for minimum, maximum, and mean of TL in mm Fig. 28 Acroteriobatus leucospilus, BMNH 1905.6.8.12, subadult male syntype, 416 mm TL, in total dorsal view. The photograph was taken and kindly provided by Kevin Webb Fig. 29 Acroteriobatus leucospilus , BMNH 1905.6.8.12, subadult male syntype, 416 mm TL, in total ventral view. The photograph was taken and kindly provided by Kevin Webb Fig. 30 Acroteriobatus leucospilus , SAIAB 34588, gravid female, 690 mm TL, in total dorsal view. Photograph courtesy Marsha Englebrecht © Fig. 31 Acroteriobatus leucospilus , underwater photograph showing the vivid live coloration. The photograph was taken and kindly provided by Dennis King Fig. 32 Acroteriobatus leucospilus , BMNH 1905.6.8.12, subadult male syntype, 416 mm TL, head in dorsal view. Scale bar: 2 cm. The photograph was taken and kindly provided by Kevin Webb Fig. 33 Acroteriobatus leucospilus , SAIAB 34588, gravid female, 690 mm TL, close-up of orbital and spiracular region. Photograph courtesy Marsha Englebrecht © Fig. 34 Acroteriobatus leucospilus , BMNH 1905.6.8.12, subadult male syntype, 416 mm TL, head in ventral view. Scale bar: 2 cm. The photograph was taken and kindly provided by Kevin Webb Fig. 36 Acroteriobatus leucospilus , SAIAB 34588, gravid female, 690 mm TL; first dorsal ( a ), second dorsal ( b ), and caudal ( c ) fins in lateral views. Photograph courtesy Marsha Englebrecht © Fig. 35 Acroteriobatus leucospilus , SAIAB 34588, gravid female, 690 mm TL, close-up of mouth-nasal region. Photograph courtesy Marsha Englebrecht © Fig. 37 Acroteriobatus leucospilus , BMNH 1905.6.8.12, subadult male syntype, 416 mm TL, radiograph of cranium and snout in dorsal view. The radiograph was taken and kindly provided by James Maclaine and reworked by Nemo Martin Table 3 Acroteriobatus leucospilus , morphometrics and meristics
Acroteriobatus leucospilus , subadult male syntype, BMNH 1905.6.8.12 Acroteriobatus leucospilus , juvenile male syntype, BMNH 1920.7.23.1 Minimum ( n = 9) Maximum ( n = 9) Mean ( n = 11) SD
mm % TL mm % TL % TL % TL % TL
Total length (mm) 416.0 100.0 248.0 100.0 223.0 960.0 498.8
Disc width, max 137.0 32.9 91.0 36.7 31.5 36.3 33.3 1.8
Disc length, direct/point-to-point (ptp) 166.0 39.9 105.0 42.3 37.0 43.9 40.0 1.8
Head length, dorsal (to occipital joint) 110.4 26.5 65.8 26.5 24.0 29.2 27.0 1.5
Head length, ventral (to 5th gill slit), ptp 102.4 24.6 67.0 27.0 22.9 28.3 25.1 1.7
Snout length, presocket 55.5 13.3 31.4 12.6 10.6 14.8 12.6 1.0
Orbit diameter, ptp 13.6 3.3 7.5 3.0 2.3 4.5 2.9 0.6
Spiracle length 10.5 2.5 6.9 2.8 2.0 2.4 2.2 0.2
Orbit and spiracle length 18.2 4.4 12.4 5.0 4.0 6.3 4.7 0.6
Interorbital width 1 (skeletal) 15.4 3.7 10.0 4.0 3.5 4.7 3.9 0.3
Interspiracular width 21.7 5.2 14.4 5.8 4.7 6.3 5.2 0.5
Preoral length 62.7 15.1 40.7 16.4 12.5 17.5 14.6 1.5
MOW, mouth width 25.0 6.0 15.4 6.2 5.3 7.2 5.9 0.5
Prenarial length, ptp 50.1 12.0 31.1 12.5 9.9 13.9 11.9 1.0
NOW, nostril length 12.2 2.9 8.7 3.5 2.4 4.0 3.2 0.6
AAW, anterior nasal aperture, width 4.7 1.1 3.1 1.3 0.9 1.8 1.3 0.3
ANF, anterior nasal flap, base length 12.0 2.9 9.3 3.8 2.4 3.9 3.3 0.6
ANW, anterior nasal flap, width 5.8 1.4 4.1 1.7 1.2 1.9 1.5 0.2
PLT, posterolateral nasal flap, total length 9.7 2.3 4.8 1.9 1.8 2.7 2.2 0.3
PLW, posterolateral nasal flap, width 2.3 0.6 2.4 1.0 0.4 0.9 0.6 0.2
PNF, posterior nasal flap, base length 7.2 1.7 4.8 1.9 1.2 2.7 1.8 0.4
PNW, posterior nasal flap, width 3.9 0.9 2.2 0.9 0.7 1.3 0.9 0.2
INM, distance between lateral margins of anterior apertures 36.5 8.8 24.3 9.8 6.9 10.8 8.7 1.1
INW, distance between posterior margins of nostrils 13.3 3.2 9.5 3.8 2.6 3.6 3.1 0.4
INA, distance between insertions of anterior nasal flaps 1.8 0.4 1.0 0.4 0.3 1.2 0.6 0.3
Shortest direct distance from anterior opening of nostril to disc margin 18.1 4.4 13.1 5.3 4.2 6.1 5.1 0.6
Gill opening width, 3rd 7.5 1.8 4.2 1.7 1.2 2.2 1.6 0.3
Distance between first gill openings 48.7 11.7 34.7 14.0 10.9 12.5 11.8 0.9
Distance between fifth gill openings 34.7 8.3 24.1 9.7 8.0 8.9 8.5 0.5
Pelvic fin, length 69.6 16.7 40.7 16.4 14.6 17.7 16.8 0.9
Pelvic fin, anterior margin length 33.3 8.0 17.9 7.2 7.1 9.5 8.0 0.8
Pelvic fin, width 30.1 7.2 18.6 7.5 5.8 7.6 6.8 0.5
Pelvic fin, base length 35.1 8.4 21.7 8.8 7.8 12.1 9.8 1.5
Pelvic fin, inner margin length 38.6 9.3 21.8 8.8 5.7 9.9 7.8 1.3
First dorsal fin, length 26.1 6.3 15.2 6.1 5.8 6.8 6.3 0.3
First dorsal fin, anterior margin length 36.6 8.8 21.0 8.5 7.6 8.9 8.3 0.4
First dorsal fin, height 28.6 6.9 15.8 6.4 5.8 8.2 7.1 0.7
First dorsal fin, base length 16.9 4.1 10.0 4.0 4.1 5.1 4.4 0.3
First dorsal fin, inner margin length 9.8 2.4 5.4 2.2 1.5 2.7 2.1 0.3
Second dorsal fin, length 26.8 6.4 15.7 6.3 6.0 7.6 6.5 0.4
Second dorsal fin, anterior margin length 37.4 9.0 21.9 8.8 1.9 9.2 8.0 2.0
Second dorsal fin, height 25.9 6.2 16.9 6.8 6.1 8.3 6.8 0.6
Second dorsal fin, base length 17.5 4.2 10.9 4.4 4.1 5.4 4.6 0.4
Second dorsal fin, inner margin length 9.6 2.3 6.1 2.5 1.4 2.7 2.1 0.4
Table 3 (continued)
Acroteriobatus Acroteriobatus Minimum Maximum Mean SD
leucospilus , subadult male syntype, BMNH 1905.6.8.12 leucospilus , juvenile male syntype, BMNH 1920.7.23.1 ( n = 9) ( n = 9) ( n = 11)
mm % TL mm % TL % TL % TL % TL
Caudal fin, dorsal margin 57.7 13.9 31.8 12.8 9.2 13.9 12.1 1.4
Caudal fin, preventral margin 34.7 8.3 16.0 6.5 6.5 9.0 7.7 0.9
Snout to pelvic-fin origin ptp 149.5 35.9 92.9 37.5 33.9 39.5 36.7 1.5
Snout to anterior vent 160.0 38.5 100.1 40.4 38.2 42.6 39.7 1.2
Snout to first dorsal-fin origin 245.0 58.9 146.8 59.2 58.8 61.4 59.8 0.9
Snout to second dorsal-fin origin 309.2 74.3 185.1 74.6 74.4 77.1 75.5 0.9
Snout to upper caudal-fin origin 356.6 85.7 212.7 85.8 83.0 89.4 86.7 1.8
Snout to lower caudal-fin origin 363.0 87.3 217.0 87.5 86.5 91.8 88.7 1.6
Pelvic-fin insertion to dorsal-fin origin 66.3 15.9 30.1 12.1 13.0 23.9 16.0 3.8
Interdorsal distance 47.1 11.3 28.9 11.7 9.9 13.4 11.6 1.0
Disc width, anterior orbit 79.7 19.2 53.2 21.5 16.9 23.8 19.5 2.2
Body width, pelvic insertion 44.0 10.6 25.4 10.2 9.8 11.7 10.7 0.5
Body width, first dorsal-fin origin 43.3 10.4 22.8 9.2 9.0 11.2 10.1 0.8
Body width, second dorsal-fin origin 21.7 5.2 11.1 4.5 4.2 5.4 4.7 0.4
Body depth, maximum 15.5 3.7 11.9 4.8 4.8 6.5 5.2 0.7
Body depth, pelvic-fin insertion 18.2 4.4 10.4 4.2 4.1 5.2 4.5 0.3
Body depth, first dorsal-fin origin 13.3 3.2 7.7 3.1 3.4 4.2 3.6 0.3
Body depth, second dorsal-fin origin 8.9 2.1 5.3 2.1 2.0 2.7 2.3 0.2
Caudal peduncle length = dorsal (D2) - caudal space 28.8 6.9 17.0 6.9 6.1 8.2 7.1 0.6
Tail length from anterior vent 256.0 61.5 147.9 59.6 57.4 61.8 60.3 1.2
Angle before eyes, ° 68.0 75.0 70.6 80.5 74.4 3.7
Individual values for the subadult male syntype (BMNH 1905.6.8.12) and the juvenile male syntype (BMNH 1920.7.23.1), ranges for all examined nontype specimens ( n = 9), as well as means and standard deviations (SD) for all 11 examined specimens are presented. Proportional values are expressed as percentages of total length (TL) 70% ethanol preserved except for minimum, maximum, and mean of TL in mm Key to the 10 valid species of Acroteriobatus 1 Snout dorsally with elongated bluish-gray spots, giving it a stripe-nosed color pattern (6 species) ………................................ 2 - Snout dorsally lacking a stripe-nosed pattern, ventrally plain light to white without a dark blotch (4 species) ............................. 7 2 Snout short and obtusely angled (~88°), disc heart-shapedwith convexanterior margins ……… A. salalah (NW Indian Ocean: Socotra Islands to Pakistan ) - Snout longer and narrowly pointed, disc wedge-shaped with nearly straight to slightly concave anterior margins ...................... 3 3 Snout with only a few, somewhat elongated bluish-gray spots, giving it a very reduced stripe-nosed appearance, maximum size of 622 mm TL …................................................................……… A. stehmanni sp. nov. (NW Indian Ocean: Socotra Islands) - Snout with pronounced stripe-nosed pattern, maximum size of 750 mm TL or larger ………………..................................... 4 4 Snout with orange stripes between the elongated bluish-gray spots, snout acutely angled at 59–64°, only few bluish-gray spots on disc, tail, and fins; maximum size of 750–790 mm TL ………………...............................................................................… 5 - Snout without orange stripes, snout lessacutely angled at 68–85°, pronounced pattern of bluish-gray spots on disc, tail, and fins; maximum size of 960 mm TL or larger ……………..........................................................................................................…… 6 5 Dorsal surface greenish brown with numerous large dark brown blotches all over the dorsal surface; ventral surface may be covered with small dark spots ………………………………………… A. zanzibarensis (NW Indian Ocean: Zanzibar , Kenya ) - Dorsal surface sandy brown with a strong orangish touch, particularly on snout, and without distinct dark blotches; no specimens withdark ventral spots apart fromunderside of snout known ..........................…… A. variegatus (N Indian Ocean: India , Sri Lanka ) 6 Snout angle 79–85°, nasal lamellae 45–48, bluish-gray but no dark brown spots dorsally on central disc, outer edges of pelvicfin margins white, lateral tail folds striped orange and white, ventral snout with black blotches or spots, maturing size above 602 mm TL, maximum size of more than 1000 mm TL ……………… A. andysabini sp. nov. (W Indian Ocean: Madagascar ) - Snout angle 68–81°, nasal lamellae 37–41, no bluish-gray but dark brown spots dorsally oncentral disc, outer edges of pectoral-and pelvic-fin margins blue, lateral tail folds white or striped blue and brown, ventral surface plain white, maturing size of 415–565 mm TL, maximum size of 960 cm TL ………………… A. leucospilus (W Indian Ocean: South Africa to Tanzania ) 7 Disc shovel-shaped, snout obtusely angled at ~95°, posterior margin of each spiracle with only one dermal fold …….................................................................................................… A. blochii (SE Atlantic Ocean: South Africa to Namibia ) - Disc wedge-shaped, snout acutelyangled at ~60–70°, eachspiracle with twodermal folds on posterior margin ………................. 8 8 Dorsal surfacebrownish with numerous smallsymmetrically arranged ocelliconsisting of awhite center surroundedby adarker brown rim, snout tip very narrowly pointed, disc narrow (length 1.3–1.4 times width) ........ A. omanensis (NW Indian Ocean: Gulf of Oman ) - Dorsal surface with dark spots or small ocelli, but each ocellus either consisting of a small central dark spot surrounded by a dark-edgedpale ringor with bluish-gray centersurrounded bya dark brown ring, snout tip less narrowly pointed, disc relatively broad (length ~1.1 times width) …………….......................................................................................................……………... 9 9 Dorsal surface light brown with a more or less symmetrical pattern of either dark spots (Natal area) or small ocelli, each consisting of a small central dark spot surrounded by a dark-edged pale ring (South African Cape Province ) …….................................................................................… A. annulatus (SE Atlantic and W Indian oceans: South Africa ) - Dorsal surface brownish with numerous irregularly shaped ocelli with bluish-gray centers surrounded by a dark brown rim ……...................................................................................................................… A. ocellatus (SW Indian Ocean: South Africa )