- Key to adult fish ( mature males especially)

- Key to the egg cases.

- Snout relatively stiff; pectoral fin supporting cartilage not reaching tip of snout; both malar and alar hooks present on mature males.               ( Genus Raja )

- Snout soft and flexible; pectoral fin supporting cartilage extending to tip of snout; alar hooks absent.                                                  ( Genus Bathyraja )

- Anterolateral edge of pectoral fin concave.

- Anterolateral of pectoral fin convex.

3 (2)

- Ventral side light; pelvic fin shallowly notched'

     Raja ( Dipturus) binoculata   ( Girard, 1854 )

big skate

       Range:   Bering Sea – San Quintin Bay, Baja California

3-800m

Dorsal dark gray, brown or reddish brown, usually with large ocellus at base of
pectoral, may have white rosette spots; white ventrally.

Tail with lateral fold.
Mid-dorsal spine row usually with single muchal spine, gap, then followed with
spines on pelvic region and caudal spines; dorsal row of caudal spines on female may
be staggered; orbital spines may be buried in skin in large adults.

Ventral pore rows approach edge of disk on rostrum; postero-lateral segment of
ventral pore row with right angle laterally to 3^rd - 4^th gill slit, more than 15 pores posterior
to the 5^th gill opening; pores not extending onto pelvic arch.

3 

- Dark ventrally, especially anteriorly

(4)

4 (3) 

Mid-dorsal row of body spines discontinuous;pelvic fin deeply notched, when held at right
angles to body they form 2 lobes.

Raja rhina   ( Jordan & Gilbert, 1880 )

longnose skate

Range: Shumagin Islands, Alaska – Pt. Loma, California

55 – 680m

Fig. : Baxter #904,1219A

    Dark to light brown with darker blotches dorsally; may have small ocellate markings at
base of pectoral fins on dorsal side, spots with light center and dark rim; ventrally darker,
may be more bluish, generally darker anteriorly; mouth white, lips dark.
    Snout strongly projecting; antero-lateral marginof pectoral concave.
    Posterior mid-dorsal row of spines on body starts with a double row; mid-dorsal spines on
tail very uneven in spacing and size; in addition there are strong spines, generally paired on
top of tail; may have fine spines ventrally on snout and front edge of pectoral in large
adults; mature female with 3-6 spines dorsally on snout; dorsal fins with fine spines.
    Ventral pores laterallyof gill slits scattered, extending to more than 70% of distance from
rear gill slit to edge of disk; pores on pelvic arch 6-15, extending laterally to beyond
insertion of pelvic fin.
    Males smaller than females.

- Mid-dorsal row of spines continuous.

Raja ( Amblyraga ) badia   ( Garman, 1899 )

broad skate

Range: Vancouver Is., British Columbia – Panama

846-2311m

   Dorsally colored medium gray-brown to chocolate-brown with darker spots and blotches,
light beneath eyes, brown bar across scapular region; ventrally dark with light blotches.
   Snout pointed.
   Interdorsal fin length0-0% TL
   Mid dorsal spine row continuous; coarse denticles on dorsally on disk and tail covering
most of the body, enlarged spines on tip of snout; tail with enlarged row of spines along
side larger mid dorsal row; ventrally smooth.

5 (2)

- Scapular spines present.

(6)

- Scapular spines absent

6 (5)

- Pelvic fin deeply notched.

Raja stellulata ( Jordan & Gilbert, 1880 )

starry skate

18-732m

          Miller & Lee, 1972:46-47

Notes:  NODC #8713040111;   NMFS #00450

   Brown or gray-brown, often spotted or with ocellus.
   Snout short, soft, rounded or broadly angulated; disk much broader than long; antero-
lateral edge of disk convex; lateral fold on tail, strongest posteriorly
   Small spines dorsally and on mosst of ventral side; mid-dorsal row of spines may or may
not be continuous; cluster of moderate spines along edge of pectoral fin from tip to snout;
spines larger on males than on females; ventral pores extend onto pelvic arch with 3-6;
pores laterally of gill openings scattered.

- Pelvic fin notch shallow.

Raja ( Amblyraga ) badia   ( Garman, 1899 )
SEE # 4

broad skate

7 (5)

- Dark spots dorsally: pelvic fin deeply notched.

Raja stellulata ( Jordan & Gilbert, 1880 )
SEE # 6 (5)

starry skate

- Not spotted dorsally, but may have blackish ocellus; pelvic fin shallowly notched.

Raja inornata ( Jordan & Gilbert, 1880 )

california skate

Range: Strait of San Juan de Fuca - Baja California

18-1600m

    Olive brown dorsally ocellus become fainter on adults; tan ventrally: Moderately long,
acutely pointed snout; Interorbital space narrow, concave; jaws somewhat curved; female with
strong lateral row of spines on caudal; dorsal spines very small along mid back, changing
opposite mid pelvics into a series of rather strong, hooked spines; ventral pores not extending
onto pelvic arch; pores lateral of gill openings scattered, not forming longitudinal rows.

8 (1)

- Ventral side dark or same color as dorsal side

- Ventral side white, may have dark mottlings, especially on tail.

9 (8)

- Mid dorsal spine row continuous from nuchal to dorsal fin with roughly same sized spines.

Bathyraja lindbergi ( Ishiyama & Ishihara, 1977 )

commander skate

Range: Kamchatka – Bering Sea

160-950m

  Body gray to dark brown to black dorsally; ventrally may be lighter, uniformly gray, 
except for mouth which has white lips with or without gray area and slightly darker snout,
tail, and around anus; tips of anterior lobe of pelvic fin dark dorsally; eye lid lighter than body.
   Interorbital space slightly concave; spiracles noticeably open dorsally, ventrally with lateral
projection of “lip” below spiracle.
   Mid-dorsal row of spines continuous; dorsal body spines relatively sparse, with abdominal 
and brachial regions almost scaleless; dorsal spines slightly stronger on snout and along 
mid line area; Lateral spines fading on body; small spines between caudal and mid dorsal 
spine row; dorsal fins and caudal fin with very fine spines; no spines ventrally; eye lid may
have fine scattered spines.
   Gill covers evenly rounded or slightly sigmoind shaped without any flap.
   Teeth stronger than is general for genus
   Clasper teeth enlarged, club shaped at distal end; projection, knife, purse and

pseudosiphon #1 present.

- Mid dorsal spine row discontinuous or nuchal portion absent, spines markedly uneven in size

(10)

10 (9)

- Nuchal spines absent.

- Nuchal spines present.

11 (10)

- Mid dorsal spines absent or very weak on tail

Bathyraja tobitukai ( Hiyama, 1940 )

Range: Western Bering – Japan

    Body grayish on both sides.
    Mid dorsal spines absent on body, absent or very weak on caudal; dorsally evenly
covered with coarse spines.

- Mid dorsal spines present on tail.

12 (11)

– Fine spines ventrally.

Bathyraja spinosissima ( Beebe & Tee-Van, 1941 )

white skate

Range: Oregon – Panama
Refer : Miller & Lee, 1972:46, 48

800-2938m

   Pale gray dorsally and ventrally.
   Wide gap between dorsal fins.
   Very fine spines both ventrally and dorsally on body; mid=dorsal row of spines absent
on body; without lateral row of spines on tail; ventral pores not more than 10 laterally of
5^th gill opening.

- Ventrally smooth ( may have ventro-lateral spines on tail )

13 (12)

– Interorbital width more than 19% HL

Bathyraja trachura ( Gilbert, 1892 )

roughtail skate
( black skate )

Range:  Western Bering Sea – Northern Baja California

490-1993m

    Plum-brown to black to slate gray dorsally and ventrally; whitish tip of anterior lobes,
margin of anus, gill openings, inside spiracles, mouth, lips, and ventral brachial area; may
have large white blotch over dorsal branchial area.
    Interorbital space concave to flattish-concave.
    Dorsal fins small, equal, prickly, interdorsal space 1-18% of length of 1^st dorsal fin base;
distance from eye to nearest point of disk margin 8.3-9.2% TL
    Dorsally covered with moderate sized spines which tend to be long and hooked, especially
posteriorly; body spines sprse over branchial area and on pectoral centers: spines crowded in
interorbital space: ventrally without spines; nuchal area of mid dorsal spine row usually
without spines, but may have 3 or less; lateral row of spines on tail slightly enlarged, smaller
spines dorsally and between mid dorsal row
    Ventral pores hard to see on the dark background; pores not onto pelvic arch.
    Pseudobranchial folds 14-16.
    Clasper with global tip; large pseudosiphon #1 present proximally near outer lateral edge
of lobe; inner surface of dorsal lobe with pseudosiphon and cleft; no component on inner
surface of ventral lobe.

- Interorbital width less than 20% HL

14 (13)

– Lateral keel extends less than half of distal portion of tail.

Bathyraja isotrachys   ( Gunther, 1877 )

challenger skate

Range:  Western Kamchatka – Pacific coast of Japan – Okinawa Trough

650-1100m

    Dorsally uniform brownish-gray to plum-brown: ventrally brownish-black to plum-brown;
whitish around mouth, tip of anterior pelvic lobes, margin of anus, and gill openings.
    Disk wider in males than in females; snout rather produced, anterior margins meeting at
nearly a right angle; tail much longer than body in males and only slightly longer in females;
interorbital space concave to flat.
    Interdorsal distance 0 – 6.7% HL; pelvic fin notch shallow to moderate; dorsally body and
tail thickly covered with minute spines; ventrally usually without prickles, but may have them
ventro-laterallyon tail; mid-dorsal spine row discontinuous, may have irregular row of 18
small spines posterior of nuchal spine row; scapular spine may have smaller, but enlarged
spine postero-lateral to it; caudal row continuous; caudal spines tend to be longer than nuchal;
no enlarged lateral spines on tail but smaller spines next to and between dorsal row; smaller
spines on eyeballs; orbital and interorbitalspines same size as rest of bodyspines.
    Gill flaps evenly rounded, without any projection; pseudobranchial folds 11 – 16.
    Claspers with pseudosiphon #1 near outer lateral edge of upper surface; inner surface of
dorsal lobe with pseudosiphon and cleft, ventral lobe with projection, sentina, and knife-like
sentinal.
    Differs from other dark bellied skates, except for B. minispinosa by narrow interorbital
width, less than 19% HL; clasper with pseudosiphon #1 only.

- Lateral keel on tail extends length of tail.

Bathyraja fedorovi   ( Dolganov, 1984 ? )

Range: Okhotsk - Pacific coast of Japan

1370 – 1550m

Refer : Dolganov, 1984?:fig.4

    Body dark-cinnamon on both sides, dorsal surface monotone, ventral surface with
numerous small white spots.
    Snout pointed, snout angle less than 90 degrees; eyes moderately small; pectoral fin
rays 71 - 72 ; pelvic fin rays 20 – 21; spiral valve turns 9.
    Egg capsules 86x48mm
    Differs from B.isotrachys by long lateral tail folds and presence of spines on central
portion of pectoral fin in adults.

15 (10)

– Interorbital width less than 20 % HL

- Interorbital width more than 20 % HL

16 (15)

– Inner margin of eye ball generally conspicuously whitish.

Bathyraja minispinosa ( Ishiyama & Ishihara, 1977 )

whitebrow skate

Range: Kamchatka – Bering sea

    Body gray dorsally and ventrally, may be lighter ventrally, light colored line between
ventral pore rows, ventral pores dark, lips white; Interorbital space generally white about
the eyes.
    Dorsal fins with very slight interspace; lateral tail fold extends almost length of tail,
wide on posterior quarter of tail; interorbital space broadly concave with small spines;
mid-dorsal spine row discontinous; nuchal spines may be small; dorsal spines small,body
covered except for brachial area and pelvic fin; slightly larger lateral spines on tail which
continue forward as an irregular row to scapular region; spines on dorsal fins and a few
on caudal fin; small spines between mid-dorsal spines; no spines ventrally; eye with small
spines.
    Gill flap with slight, rounded projection.
    Clasper pointed distally with pseudosiphon #2; projection of clasper rudimentary;
purse and knife of clasper absent.

- Inner margin of eyeball same color as dorsal ground color.

17 (16)

– Nuchal spines very weak, not sharp, numbering 0-3; clasper tip roundish with with
tip of projection showing, without pseudosiphon #1, knife and purse present.

Bathyraja Isotrachys ( Gunther, 1877 ) 
            SEE #14 (13)

challenger skate

- Nuchal spines strong, sharply pointed, numbering 3.

Bathyraja matsubarai   ( Ishiyama, 1952 )

Range: North Pacific off Japan.

800-1205m

    Body dark purplish brown on both sides, area around mouth whitish.
    Eye relatively large; dorsal fin interspace narrow, distance 7.4% HL; interorbital space
concave; lateral tail fold narrow, extending 53.6 % of posterior portion of tail; pelvic fin
notch dep; mid-dorsal spine row discontinuous; mid dorsal spines large, smooth, with even,
oval bases; body covered with small spines, includung spines between and around
mid-dorsal row of spines on tail, lateral tail spines not larger than rest of tail spines; spines
absent over brachial area and central portion of pectoral fin; dorsal and caudal fins with
spines; pelvic fins without spines exceptfor small patch on central area of posterior lobe.
    Clasper with pseudosiphon.

18 (15)

– Clasper ventral lobe without any components; vertebrate precaudal count 62 – 55.

Bathyraja trachura ( Gilbert, 1892 )
        SEE # 13

( black skate ) roughtail skate

18 (19)

– Clasper ventral lobe with components; Vprd count more than 66

19 (18)

– Body mottled with many, moderately sized, scattered white markings dorsally.

Bathyraja maculata   ( Gilbert, 1892 )

white blotched skate

Range; Kamchatka – Bering Sea
Refer : Baxter #949,1051
            Ishiyama & Ishihara, 1977:80, figs.7D, 8D,13A-B
Notes : NMFS #00480
Resem: Differs from sp. #742 by having large yellow spots and smaller
            mid-dorsal and scapular spines.

190 – 570m

    Gray dorsally and ventrally; large scattered white to yellow blotches dorsally.
    Interorbital space concave.
    Pelvic fin notch moderate; broad lateral tail fold.
    Body dorsally mostly covered with small spines, ventrally without spines; 
ventral pores 4 + 7 +5
    Clasper with large pseudosiphon.

- Body without munerous white markings.

20 (19)

– Eye length less than dorsal spiracle length, clasper sentinal absent.

Bathyraja caeluronigricans ( Ishiyama & Ishihara, 1977 )

Range: Northwestern Pacific to Okhotsk Sea.
Refer : Amaoka, et al, 1983:169, fig.12; 311, fig.112
           Ishiyama & Ishihara, 1977:74, figs.9A-B, 10A
Notes : Type MTUF 21803

200-1000m

    Body black on both sides, area around mouth white.
    Eye small, size about 75 % spiracle length, 22 % snout length, 54 % interorbital width.
    Mid dorsal spine row discontinuous; margin of dorsal side with scattered, small spines,
spines absent in central area of body; spines sparse on interorbital space and eye ball;
ventrally smooth without spines.
    Claspers with pseudosiphon.

- Eye length as long or longer than spiracle opening; clasper sentinel present.

21 (20)

– Ventral side with fine spines.

Bathyraja abyssicola   ( Gilbert, 1896 )

deepsea skate

Range: Bering Sea – Baja California; Japan
Refer : Amaoka, et al, 1983: 168,   fig.9
           Ishihara & Ishiyama, 1985 fig.   4A
           Masuda, et al, 1983:13,   pl.15(A)
           Zorzi & Anderson, 1988:93,   fig2:
Notes : Holotype USNM 48623;   NODC #8713040101;   NMFS #00410

362-4000m

Uniform whitish tan to dark brown both ventrally and dorsally; may have a few darker
spots dorsally; ventral tail somewhat darker, whitish areas around mouth, anterior margins of
gill openings, nostrils, and tip of clasper whitish.

Snout pointed, angle less than 90 degrees; interorbital space deeply concave, wider than orbit
length; spiracles as large as orbits and separated from each by twice the distance of their
length; tail a little more than half total length, lateral fold on tail from about mid tail,
interdorsal space moderately narrow, 2.3 % HL; scapular spines reduced or absent in young
and large adults; fine spines on dorsal and usually on ventral surfaces, bare areas on extreme
anterior margin of disk, posterior margin, orbit region, outer portion of pelvic fins, and basal
area of tail; ventral pores with inner row with more than 20 laterally of gill openings.

Claspers long, slender, flexible, oval tip; posterior third of upper surface with fine spines;
pseudosiphon #1 present proximally near outer lateral edge of upper surface; inner surface of
dorsal lobe with distinct pseudorhipidion and cleft, that of ventral lobe with projection,
sentina with knife-like sentinel.

- Ventrally without spines

22 (21)

– Coloed plum-brown; distance between posterior margin of pseudosiphon #1
and tip of clasper as long as length of pseudosiphon #1.

Bathyraja matsubarai   ( Ishiyama, 1952 )
        SEE # 16

- Colored grayish-brown; Distance between posterior margin of pseudosiphon #1

and clasper tip longer than length of pseudosiphon #1

Bathyraja notoroensis   ( Ishiyama & Ishihara, 1977 )

Range: Northwestern Pacific – Japan: Okhotsk Sea
Refer : Amaoka, et al, 1983:311, fig.113
           Ishiyama & Ishihara, 1977:78, figs.7C, *c, 12A-B
Notes : TypeMYUF221817
Resem: Differs from B.matsubarai and B.caeluroigrieans by body color and eye size.

600m

Body dark grayish-brown on both sides; whitish around mouth.
Eye large, length about spiracle length, 65% interorbital width.
Mid-dorsal spine row discontinuous; dorsal spines absent or very weak;
    eye ball without spines.
Clasper rather short with shallow cleft.

23 (8)

– Mid dorsal spine row continuous.

- Mid dorsal spine row discontinuous or absent

24 (23)

– Adults with fine spines other than on snout ventrally on body.

- Ventrally smooth, withoutspines other than may be on snout.