Pristiophorus lanae, Ebert, David A. & Wilms, Hana A., 2013

Ebert, David A. & Wilms, Hana A., 2013, Pristiophorus lanae sp. nov., a new sawshark species from the Western North Pacific, with comments on the genus Pristiophorus Müller & Henle, 1837 (Chondrichthyes: Pristiophoridae), Zootaxa 3752 (1), pp. 86-100 : 87-97

Pristiophorus lanae sp. nov.

Lana’s Sawshark

( Figures 1–4 , Tables 1 , 2 )

Pristiophorus cirratus: Fowler, 1941: 280 (USNM 10107; now USNM– 151231 according to Springer & Bullis, 1960). Pristiophorus japonicus: Compagno, 1984: 134 , Philippines sawsharks possibly referable to this species.

Pristiophorus sp.: Springer & Bullis, 1960: 10(2): 253; Compagno, 1998: 1236, fig.

Pristiophorus sp. C: Compagno et al., 2005a: 135, ill., pl. 16; Compagno et al., 2005b: 57; Ebert et al., 2013: 182, fig., pl. 19.

Holotype. CAS 34942, 775 mm TL, female, NW of Baltazar Island, Marinduque, Philippines, ca. 13° 23’ N, 121° 79’ E, 163–168 fa. (298–307 m), 10 December 1966, collected by J.E. Norton.

Paratypes. CAS 34930, 725 mm TL, female, south of Barrio Salong, Balayan Bay, Luzon Island, Batangas, Philippines, ca. 13° 44’ N, 121° 00’ E, 125–135 fa. (229–247 m), 18 July 1966, collected by J.E. Norton; CAS 236420, 669 mm TL, male, NW of Baltazar Island, Marinduque, Philippines, ca. 13° 23’ N, 121° 79’ E, 163–168 fa. (298–307 m), 10 December 1966, collected by J.E. Norton.

Non-types. CAS 34193, 396 mm TL, female, Siburio Point, Ragay Gulf, Camarines Sur, Philippines, ca. 13° 33’ N, 122° 48’ E, 319–324 fa. (584–593 m), 24 November 1966, collected by J.E. Norton; Mark Harris Collection (3 specimens), PMH 271-01, 830 mm TL, female, 271-02, 673 mm TL, female, 271-03, 613 mm TL, female, all landed at the Pasil fishing port, Cebu, Philippine Islands, caught by bottom trawlers operating in the Bohol Sea, ca. 350 m, 8 May 2008, collected by Mark Harris.

Diagnosis. A slender bodied five-gilled sawshark distinct from other members of the genus by a combination of characteristics including a narrow, relatively long rostrum, with a pre-oral length 27.5–30.6% TL, a pre-barbel length of 51–55% of pre-oral length, and a rostral width at nostrils of 4.8–6.1 times pre-orbital length. Barbels located closer to the mouth than to rostral tip. First dorsal fin originates posterior to free rear tip of pectoral fin. Lateral dermal denticles unicuspidate, mostly flat, and imbricated. Coloration is a uniform dark brown above, lighter below; no bars, blotches or other distinctive markings.

Description. Proportional measurements expressed as a percentage of the total length (TL) are given for the holotype followed by the paratypes in parenthesis; partial measurements from a non-type specimen (now skeletonized) are included when available ( Table 1 ).

Pristiophorus lanae

Holotype Paratype Paratype non-type CAS 34942 CAS 34930 CAS 236420 CAS 34193 ... continued on the next page Pristiophorus lanae

Holotype Paratype Paratype non-type CAS 34942 CAS 34930 CAS 236420 CAS 34193 ...continued on the next page Pristiophorus lanae

Holotype Paratype Paratype non-type CAS 34942 CAS 34930 CAS 236420 CAS 34193 Body slender, snout elongated, flattened, forming blade-like rostrum, narrowing anteriorly to tip; pre-barbel length 13.9 (14.3–16.7)% TL; snout angle 13.0° (10.6°–12.5°). Head strongly depressed over eyes, laterally expanded, very narrow, subtriangular, head width at mouth 6.3 (5.8–6.1)% TL, height greatest at first gill opening 3.3 (3.3)% TL; head width at nostrils 6.4 (5.5–6.6) times in pre-orbital length. Trunk cylindrical, subcircular in cross-section, not flattened and ray-like, narrow, tapering toward caudal origin; head length 0.6 (0.5) times trunk length; pectoral-pelvic space 15.1 (13.9–16.0)% TL; dorsal-caudal length 10.2 (8.7–9.2)% TL; caudal peduncle height at second dorsal insertion 3.8 (3.2–3.4) into dorsal caudal space, and width 0.9 (0.9–1.1) in height. Lateral keels present; no precaudal pits.

Rostrum very long, narrow and tapering; pre-oral length 27.5 (28.4–30.6)% TL; sides of rostrum relatively straight from tip to barbels, slightly convex at barbels, becoming slightly concave from barbels to nostrils. Ratio of pre-orbital length to rostrum width at nostrils 5.8 (4.8–6.1). Parallel rows of enlarged pits absent on underside of pre-barbel snout. Barbels closer to mouth than rostral tip, pre-barbel length 50.7 (50.5–54.5)% of pre-oral length; space from barbel to nostril 1.2 (1.1–1.3) times space from nostril to first gill opening; barbels ending less than 1.9 (1.6–1.8) times eye length anterior to nostrils. Large lateral rostral saw-teeth along sides of snout and head total 24 (24–42), including 18 (17–26) teeth in front of barbels and 6 (7–17) teeth behind barbels; smaller lateral rostral teeth between large lateral rostral teeth 1–3. Post-narial lateral rostral teeth extending 0.4 (0.8–0.9) times eye length behind eye. Bases of lateral and ventral rostral teeth relatively smooth. Ventral rostral teeth anterior to barbels number 14 (14), between barbels and nostril 9 (9). An enlarged ventral rostral tooth present just in front of nostril.

Eyes oval, large, lateral on head, length 2.3 (2.3–2.5)% TL; distance to last rostral tooth 0.9 (1.8); inter-orbital concave width 3.7 (3.4–3.6)% TL; sub-ocular groove present. Spiracles moderately large, length 2.0 (2.1–2.4) times eye length, slightly oblique; located just posterior to eye. Gill openings small, lateral on head, closer to ventral surface than dorsal; each similar in length; fifth gill opening arches slightly around pectoral fin origin.

Nostrils relatively small, anterior nasal flap well develop, tear-shaped; excurrent apertures transversely oval, nearly circular, width 0.8 (0.8–1.0)% TL, 3.9 (3.2–4.0) in internarial width. Distance from nostrils to mouth 1.2 (1.1–1.2) times internarial space. Distance from nostrils to barbels 1.9 (2.0–2.3) times distance between nostrils and mouth corners.

Mouth broadly arched, extending forward to about opposite posterior of eye orbit, width 4.0 (3.6–3.7)% TL. Lower labial furrows short, about 0.4 (0.3)% TL, upper labial furrows absent. Teeth with a single prominent acute cusp, in well defined rows, bases flattened and rounded. Tooth row counts 48 (36–48) on upper jaw and 44 (32–40) on lower jaw; series of functional teeth about 3–5.

Lateral trunk dermal denticles closely imbricated, with flat mostly unicuspidate crowns; outer margins of dorsal and pectoral fins scaled.

Pectoral fins large, anterior margin weakly convex, anterior margin length 11.5 (9.2–11.1)% TL, and 41.8 (31.9–38.9)% of pre-oral length; posterior margin nearly straight to weakly concave, apex broadly rounded; inner margin convex; height slightly greater than posterior margin length; free rear tip terminates anterior to origin of first dorsal fin. Pectoral fin skeletal radials divided into 2–3 segments; propterygium with one radial, mesopterygium with (10) radials, metapterygium with (12) radials, and total radial count 20 (22–23). Pelvic fins large, anterior margin 5.3 (5.7–5.8)% TL, length about equal to first and second dorsal fin lengths; anterior margin slightly convex, posterior margin weakly concave, broadly rounded at apex; inner margin nearly straight, length about 1.4 (1.4–1.6) times into posterior margin length, free rear tip narrowly rounded.

First dorsal fin broad, semifalcate, anterior margin slightly convex to nearly straight, with broadly rounded apex anterior to insertion, posterior margin slanting posteroventrally, slightly convex before tip; inner margin straight, free rear tip narrowly acute; origin about opposite or slightly behind free pectoral rear tips; insertion over pelvic fin origins or slightly anterior to them by less than a fourth of fin base, free rear tip extending to about opposite or slightly in front of pelvic insertions. Second dorsal fin subequal to first, with base and height shorter; origin behind pelvic insertions by distance about equal to or less than first dorsal fin base. Caudal fin long, dorsal margin slightly convex, length 17.2 (17.8–18.7)% TL, lower post-ventral lobe absent, upper post-ventral margin broadly rounded; terminal lobe well developed, caudal terminal margin slightly concave, apices angular.

Total vertebral count 138 (140–145), monospondylous precaudal count 44 (43–48), diplospondylous precaudal count 51 (47–50), total precaudal count 95 (90–98), and caudal count 43 (50–51). Intestinal valve turns (6).

Coloration. After preservation these sharks are a uniform medium brown above, becoming lighter ventrally; rostrum lighter except for two distinct longitudinal stripes extending length; lateral rostral teeth light colored; trailing dorsal, pectoral and pelvic fins with light to white fin edges; caudal fin terminal margin and upper post ventral margins lighter to white.

Size. The species is known from seven specimens, six females and a single male. The females range in size from 396–830 mm TL and the male measured 669 mm TL. The maturity status of the females was not determined, but the male appears to be maturing or mature based on calcification and development of the claspers.

Distribution. At present this new sawshark species is known only from the Philippine Islands, off Zamboanguita, Apo Island between Negros and Siquijor, and off southern Luzon in Balayan Bay and Ragay Gulf, although it likely has a wider distributional range in the western North Pacific. The approximate capture location for three non-type specimens, all from the Bohol Sea, was provided by Mark Harris (pers. comm.).

General Biology. Virtually nothing is known about the biology of this sawshark. It is an inhabitant of upper continental slopes in tropical waters found at depths of 229 to 593 m. Litter size unknown. It may be caught and discarded as bycatch by trawlers and other deepwater fisheries operations off the Philippines. A bony fish skeleton can be seen in the digestive tract in an x-ray of the holotype.

Etymology. The species name lanae is after shark enthusiast Lana Ebert on the occasion of her graduation from the University of San Francisco. The proposed common name is “Lana’s Sawshark”.

Comparison to other Pristiophorus species. Pristiophorus lanae can be separated from all other members of this genus by a combination of characteristics, including pre-oral rostrum length of 27.5 to 31% TL, ventral rostrum without conspicuous large pits, a pre-barbel length of 50.7 to 54.5% of pre-oral length, rostral width at nostrils of 5.2 to 6.0 times pre-orbital length, mostly flat, unicuspidate lateral denticles that are imbricated, relatively large spiracles almost three-quarters eye-length, and a uniform dark brown coloration above without bars, spots, or other prominent markings. The new species can be separated from its closest geographic congener, P. japonicus , by having a narrow, slightly longer rostrum (27.5–31% versus 26–29%TL), fewer large rostral teeth in front of rostral barbels (17–26 versus 25–32), mouth at corners extending forward to below the rear margin of the eye versus extending below the rear one-third of eye margin, a greater mouth width at 6.9–7.8 times into pre-oral length (versus 5.8–6.9), eye length into head length (15.6–15.9 versus 9.8–13.2), mouth width into head length 9.0– 10.0 versus 7.4–8.5 times, head width at nostrils 5.2–6.1 times into pre-orbital length versus 3.9–4.9 times, shorter pre-barbel length (from snout tip to barbel) of 50.7–54.5% of pre-oral length versus 53.6–59.2% ( Figure 4 ), a snout angle of 10.6°–13.0° versus 12.4°–14.6°, and lateral trunk denticles with flat crowns that are imbricated versus erect crowns that are not imbricated. The number of monospondylous vertebrae is slightly lower in P. lanae (46– 49) versus P. japonicus (51–52). Also, P. lanae appears to be a smaller species, maximum length of at least 830 mm, compared to 1530 mm TL for P. japonicus ; males appear to mature at about 669 mm TL in P. lanae , while P. japonicus males mature at about 1070 mm TL (Ebert et al., 2013).

The next closest congener to P. lanae , is the recently described P. delicatus , which can be separated by the location of their rostral barbels ( Figure 4 ); P. lanae has its barbels located slightly closer to its mouth, with a prebarbel length of 51–55% versus P. delicatus which has its barbels located about equidistance to slightly closer to its rostral tip, and pre-barbel length of 45–51%. Pristiophorus lanae also has a smaller nostril to mouth distance times internarial space ratio (1.1–1.2) compared to P. delicatus (over 1.3 times), and the spiracle length of P. lanae is relatively large, 0.75 times eye diameter, compared to P. delicatus , which is smaller, 0.43–0.59 (Yearsley et al., 2008). The number of monospondylous vertebrae is slightly lower in P. lanae (46–49) versus P. delicatus (49–55). The dorsal coloration of P. lanae is a uniform dark brown compared to a pale to medium yellowish brown in P. delicatus .

Pristiophorus lanae differs from the other two Australian species, P. cirratus and P. nudipinnis , in having a longer pre-barbel length from its snout tip to barbel, over 50% TL of pre-oral length versus less than 43% TL ( Figure 4 ). Also, P. cirratus and P. nudipinnis geographically are restricted to shallow, temperate waters of southern Australia, while P. lanae is known only from deep, tropical waters of the Philippines. The other two Pristiophorus species, P. nancyae and P. schroederi , are both deepwater species, like P. lanae , but in addition to being geographically distant, all are morphologically distinct. Pristiophorus nancyae from the western Indian Ocean is the only described member of the genus known to have a very distinctive double row of 4 to 5 conspicuous large pits anterior to the nasal barbels on the underside of its snout (Ebert & Cailliet, 2011). The western North Atlantic P. schroederi has a very elongated snout, with a pre-oral length over 31% TL ( Figure 4 ), and tricuspidate lateral denticles that are widely spaced. Pristiophorus lanae by comparison has a slightly shorter snout, 27.5–31% TL, and unicuspidate lateral denticles that are closely imbricated.

General Remarks. Compagno (1973, 1977) considered the Pristiophoriformes to be highly derived and transitional between “typical” sharks and batoids. Most subsequent authors (Shirai, 1992, 1996; de Carvalho, 1996; Compagno, 2001; Ebert & Compagno, 2013) have placed the pristiophorids as an intermediate sister group to the batoids, but kept them as a separate order to form the Squalomorphii along with the Hexanchiformes, Squaliformes , and Squatiniformes (Nelson, 2006). Interestingly, Naylor et al. (2005, 2012a, 2012b) showed that molecularly the Pristiophoriformes formed a clade with the Squaliformes and Squatiniformes to the exclusion of the Hexanchiformes. Furthermore, Naylor et al. (2012b) commented that the interrelationships between the Pristiophoriformes, Squatiniformes , and Echinorhinidae remained unclear and warranted further investigation.

The interspecific relationship of the genus Pristiophorus has been little studied and remains open to interpretation. The genus with inclusion of the heretofore describe P. lanae , includes seven valid species, all of which appear to be regional endemics with relatively restricted geographic distributions (see introduction above and Ebert & Cailliet, 2011; Ebert & Compagno, in press). The members of this genus can be subdivided into two species subgroups by habitat, one of temperate water mostly coastal, continental shelf species ( P. cirratus , P. japonicus , P. nudipinnis ) and another of tropical deepwater, continental and insular slope species ( P. delicatus , P. lanae , P. nancyae , P. schroederi ). Ebert & Compagno (in press) suggested a further subdivision that included four species subgroups based on their morphology in addition to habitat. This includes a subgroup of relatively shallowwater, temperate, stout bodied, western Pacific species ( P. cirratus , P. japonicus ), a subgroup of deepwater, tropical, mostly slender bodied species ( P. delicatus , P. lanae , P. schroederi ), and two monotypic subgroups; one subgroup comprised of the highly distinctive, deepwater, western Indian Ocean, dwarf species P. nancyae , and a subgroup consisting of the relatively large, southern Australian endemic P. nudipinnis . The genus can also be subdivided morphologically based on the relative position of the barbel ( Figure 4 ); a subgroup of species whose barbels are distinctly closer to the mouth ( P. japonicus , P. nancyae , P. nudipinnis ), about equidistant to slightly in front of or behind, the rostral midpoint between the rostral tip and mouth ( P. delicatus , P. lanae , P. schroederi ), and a subgroup with their barbels located distinctly closer to the rostral tip ( P. cirratus ). Further detailed morphological studies, combined with newer molecular methods, will be required to fully resolve the interspecific relationships between these various species. The only information available from molecular studies to date shows P. japonicus clusters closer to P. warreni rather than to P. cirratus (Naylor et al. 2012a).

Key to the species of the genus Pristiophorus : (modified after Ebert & Cailliet, 2011)

1a. A double row of 4 to 5 conspicuous large pits on underside of snout in front of barbels. Larger rostral teeth with prominent transverse ridges on their bases. First dorsal fin very broadly triangular, with apex well in front of insertion and free rear tip about over pelvic insertions............................................................. Pristiophorus nancyae

1b. No enlarged pits on pre-barbel snout. Larger rostral teeth apparently lacking basal ridges. First dorsal fin narrower and triangular to semifalcate, with apex over or behind insertion and free rear tip over or anterior to first third of pelvic bases... 2

2a. Rostrum short, broad, and strongly tapering, pre-oral length 22 to 24% of total length. Snout width at nostrils 2.7 to 4.3 times in pre-orbital length. Nostrils about equidistant between barbels and mouth corners. Nostrils diagonally oval and elongated.................................................................................. Pristiophorus nudipinnis

2b. Rostrum more elongated, narrower, and less strongly tapering, pre-oral length 25 to 32% of total length. Snout width at nostrils 4.4 to 6.1 times in pre-orbital length. Nostrils considerably closer to mouth corners than to barbels. Nostrils transversely oval, nearly circular......................................................................................... 3

3a. Body and fins with a color pattern of dark blotches and spots (occasionally faint). Pre-barbel rostrum length from only 40 to 43% of pre-oral length................................................................. Pristiophorus cirratus

3b. Body and fins uniform in color. Pre-barbel rostrum length 44 to 59% of pre-oral length.............................. 4

4a. Snout greatly elongated, pre-oral length 31% or more of total length. Lateral trunk denticles largely tricuspidate........................................................................................... Pristiophorus schroederi

4b. Snout shorter, pre-oral length 31% or less of total length. Lateral trunk denticles unicuspidate......................... 5

5a. Mouth extending forward to below posterior third of eye. 25 to 32 large lateral rostral saw-teeth in front of barbels. Barbel origin distinctly closer to mouth than to rostral tip. Tooth rows 35 to 71 in upper jaw, increasing with growth. Lateral trunk denticles with erect crowns that are not closely imbricated................................... Pristiophorus japonicus

5b. Mouth extending forward to below rear margin of eye. 17 to 26 large lateral rostral saw-teeth in front of barbels. Barbel origin more or less equidistant between mouth and rostral tip. Tooth rows 31 to 48 in upper jaw. Lateral trunk denticles with flat crowns that are imbricated.............................................................................. 6

6a. Barbels slightly closer to rostral tip than to mouth or approximately equidistant, pre-barbel length 45 to 51% of pre-oral length. Spiracles moderately large, width less than 0.5 of eye length. Distance from nostrils to mouth more than 1.3 times internarial space. Origin first dorsal fin behind pectoral free-rear tip..................................... Pristiophorus delicatus

6b. Barbels approximately equidistant or slightly closer to mouth than rostral tip, pre-barbel length 51 to 54% of pre-oral length. Spiracles large, width almost less 0.75 of eye length. Distance from nostrils to mouth about 1.1 to 1.2 times internarial space. Origin first dorsal fin about opposite to slightly behind pectoral free rear tip.............. Pristiophorus lanae new species

Figures

FIGURE 1. Pristiophorus lanae sp. nov., holotype, CAS 34942.

FIGURE 2. Pre-branchial ventral head view of Pristiophorus lanae sp. nov., holotype, CAS 34942.

FIGURE 4. Dorsal (upper row) and ventral (lower row) views of rostrums of all seven Pristiophorus species (from left to right): P. lanae (Holotype: CAS 34942), P. delicatus (Holotype: CSIRO H 931 – 01), P. japonicus (HUMZ 195735), P. nancyae (Holotype: SAM 34013), P. nudipinnis (CSIRO H 3777 - 01), P. cirratus (CSIRO H 1135), and P. schroederi (CAS 234057). All photographs by D. A. Ebert except for HUMZ (195735) by K. Nakaya.

Tables

TABLE 1. Pristiophorus lanae proportional measurements expressed as a percentage of total length (TL %) of the holotype (CAS 34942), paratypes (CAS 34930 and CAS 34942) and a non-type specimens (CAS 34193).

	F	F	M	F
Total length (mm)	775	725	669	396
Pre-caudal length	82.6	81.5	79.2	–
Pre-barbel length	13.9	14.8	14.3	16.7
Pre-narial length	23.9	25.4	24.4	26.8
Pre-oral length	27.5	29.0	28.4	30.6
Pre-orbital length	24.9	26.8	25.9	28.8
Pre-spiracle length	28.0	29.2	30.2	–
Pre-gill length	33.3	34.1	33.6	–
Pre-pectoral length	36.1	37.2	36.9	–
Pre-pelvic length	53.5	54.9	51.6	–
Snout-vent length	57.2	57.2	53.6	–
Pre-first dorsal fin length	47.4	47.3	47.1	–
Pre-second fin dorsal length	67.6	66.9	65.5	–
Inter-dorsal fin length	15.5	14.8	13.8	–
Dorsal-caudal space	10.2	9.2	8.7	–
Pectoral-pelvic space	15.1	16.0	13.9	–
Pelvic-caudal space	22.5	23.6	22.1	–
Pectoral origin-first dorsal fin origin length	11.0	-0.4	1.6	–
Pectoral origin-second dorsal fin origin length	8.5	8.3	8.7	–
Eye length	2.3	1.0	2.5	–
Eye height	1.0	1.0	1.2	–
Eye to last rostral tooth length	0.9	1.8	2.4	–
Interorbital length	3.7	3.4	3.6	–
Interbarbel width	1.8	2.3	2.5	–
Barbel length	5.3	7.2	5.7	9.3
Barbel-nostril length	9.5	10.6	10.0	10.1
Barbel tip to nostril length	4.5	3.7	4.6	2.5
Nostril width	0.8	0.8	1.0	–
Internarial length	2.5	2.8	2.5	3.8
Anterior nasal flap	0.5	0.6	0.6	–
Nostril-mouth symphysis length	3.0	3.3	3.0	4.0
Nostril-mouth rictuses (corners) length	4.9	4.7	4.3	5.1
Nostril to first gill opening length	7.9	9.4	7.9	9.6
Spiracle length	1.2	1.0	1.2	–
Spiracle width	0.4	0.4	0.4	–
Interspiracle width	3.2	3.3	3.3	–
Eye-spiracle length	0.8	0.4	0.4	–
Mouth length	1.5	1.5	1.6	–

TABLE 2. Vertebral counts, including monospondylous (MP), diplospondylous precaudal (DP), total precaudal (PC), diplospondylous caudal (DC), and total vertebrae (Total) for all seven known sawshark species. Pristiophorus lanae sp. nov., in bold.

Species n	MP	DP	PC	DC	Total
Pliotrema warreni 15	53–58	47–52	101–108	43–54	146–157
Pristiophorus cirratus 16	52–55	47–53	101–108	46–54	149–158
P. delicatus 12	49–55	50–54	101–105	46–51	149–156
P. japonicus 7	51–52	47–52	99–103	50–51	147–150
P. lanae 4	43 – 48	47–51	90 – 98	43–51	138 – 145
P. nancyae 7	42–45	45–51	90–93	44–50	132–139
P. nudipinnis 10	51–54	45–53	98–106	45–50	143–153
P. schroederi 1	–	–	100	55	155