“Graneledone antarctica, new species
Figures la–i, 2
Material studied: Holotype—male, mantle length 41 mm, from Ross Sea, Eltanin Sta. 2110, 74°05.6'S, 175°05.2'W in 2341 m with 10-foot Blake trawl, February 8, 1968, USNM 729679. Paratypes—male, mantle length 39 mm, female, mantle length 45 mm, UMML 1667. Male, mantle length 38 mm, 3 females, mantle length 25-41 mm, USNM 729680. ( All paratypes with same data as holotype.)
Description: The mantle is short, broadly rounded posteriorly, and very wide. It is distinctly flattened dorso-ventrally. The head is set off from the mantle by a slight constriction. The head is nearly as wide as the mantle, flattened, and bears large conspicuous eyes.
The funnel is of moderate size; it is free for its anterior half which is tubular and tapered. The funnel organ is VV-shaped but shows considerable variation ( Figs. la, b ). It is composed of 2 elongate oval pads slightly to moderately split anteriorly with pointed to blunt tips.
The arms are long and rather stout; the arm order is 1.2.3.4, either I or II always being the longest and IV always the shortest. The web is moderately deep with the formula C = B.D.A = E but showing some individual variation. The web extends only a short distance up the dorsal side of each arm after which there is no trace. On the ventral side of I, II, and III the web extends to the tip of the arm. It is low in the basal half but at about the midpoint of the arm it broadens, becoming widest at about the distal 1/5 of the arm. Only the extreme tip of the arm is free. On preservation, the contraction of the web curls the arm tip in a pronounced fashion. The arm web attains its greatest development on I and II. The suckers are small and in a single row on each arm. They are largest near the base of the arm and regularly decrease in size toward the arm tip.
The third right arm is hectocotylized in the male. It is bordered ventrally by a membrane or web, its outer margin thickened, cream-colored, and rolled outward. The contraction of this thickened border curls the arm tip downward resembling a hook or a slight S-curve. This shape is probably not found in the living animal but is due to the action of the preservative. The tip of the arm bears a small ligula (Fig. 1c). It is spoon-shaped, pointed distally, and has thickened margins. The oral face is crossed by about 12-13 low fleshy folds. The calamus is projecting, low, and blunt.
The gills are short, stout, and contain 6 lamellae on the outer demi‑branch.
None of the specimens appear to be sexually mature. The holotype had a well developed hectocotylus and penial apparatus but there were no spermatophores in Needham's sac nor were any found in the other males.
None of the females contained developed eggs.
The digestive tract was dissected from one of the large females (Fig. 1d). The buccal mass is large and contains large anterior salivary glands. The paired posterior salivary glands are very small and poorly developed. The esophagus leads from the buccal mass posteriorly to the crop which it enters dorsally. The latter has no diverticulum. Posteriorly the esophagus and crop lead into a stout portion which connects with a moderately large two-parted stomach, one part thick-walled and muscular, the other thin-walled. The spiral caecum is small, stout, smooth externally, and united with the small heart-shaped liver by paired hepatopancreatic ducts. The intestine is stout, thin-walled, and leads anteriorly to the anus which does not appear to have anal flaps. The crop was opened in one specimen. It contained an amorphous mass of animal tissue in which numerous polychaete bristles were embedded.
The beaks show no unusual features (Figs. le, f).
Radulas were removed from two specimens. While there is no question that all of the specimens are conspecific and show a remarkably close conformity in other characters, the radular teeth vary greatly. The radula from specimen No. 2 (Fig. 1g) has only 5 teeth in each transverse row, none of them showing any great dissimilarity. The rachidians are undifferentiated but somewhat larger than the second laterals and without cusps. The admedians or first laterals are missing. The second laterals are only slightly curved with small bases; the third laterals are largest, tallest, and broadest, with conspicuous bases. There is no trace of marginal plates.
The radula of specimen No. 3 (Fig. lh) has rather large, broad rachidians with broad bases, perhaps somewhat distorted in the figure by a sidewise orientation in the mount. The admedians are a little shorter than the second laterals, narrow and sharp. The second laterals are larger and more curved. The third laterals are very broad, almost flattened at their tips and show a slightly irregular outline. All of these teeth stand erect, are thin and transparent, and in No. 3 have very irregular almost root-like bases.
All of the specimens were fixed in 10 percent buffered formalin after brief emersion in fresh water to kill them. They were thus fixed without undue distortion of the arms and were later transferred to 70 percent alcohol. They are in remarkably fine condition for examination.
The general consistency is muscular with a thick overlying layer of almost gelatinous material, particularly posteriorly on the mantle and slightly less so dorsally, around the head and eyes, and surrounding the brachial crown. The surface is covered by a thin, very tough skin which is covered dorsally on the mantle, head and arms by numerous, evenly spaced, close-set warts (Fig. 2). These consist of a raised mound bearing from one to over a dozen small, cone-shaped papillae. They are very regularly distributed. There are none on arms IV; arms II and III are liberally covered dorsally but there are none ventrally. There is a distinct line of fine warts on the periphery of the mantle arranged like a keel running from the corners of the mantle aperture around the mantle posteriorly. Below the keel there are no warts and the surface is smooth. There are no warts beneath the head except for a few bordering the lower eyelid and immediately adjacent to it. There is a distinct circlet of warts on the eyelid (Fig. 1i). These are somewhat larger than the other warts and two or three of them over each eye are greatly enlarged and, although not erected, probably represent ocular cirri.
The color of specimens in alcohol is a pale yellowish brown dorsally, suffused with purplish hues at the base of the brachial crown and on and between the arm bases. On this ground color the mantle, head, funnel, and the base of the arms are reddish brown suffused with purple. The spermatophoral groove on the third right arm is yellowish.
TABLE 1. Measurements (in mm) of 3 male specimens of Graneledone antarctica, new species, from ELTANIN Sta. 2110.
Holotype
No.
1
2
3
Mantle length
41
39
38
Mantle width
44
37
40
Head width
40
34
38
Arm length
I
164
165
138
138
138
136
II
164
164
123
130
127
136
III
150
145
112
105
119
117
IV
135
135
103
98
113
105
Total length
208
179
178
Arm width
8.0
7.0
7.0
Hect. arm length
145
105
117
Ligula length
4.5
4.0
3.8
Calamus length
2.0
2.0
1.5
Sucker diameter
3.3
2.3
2.2
Web depth
A
28
30
25
B
46
47
35
38
33
42
C
45
52
35
35
38
38
D
33
27
30
Gills
6
6
6
TABLE 2. Indices of bodily proportions of three males of Graneledone antarctica, new species, from ELTANIN Sta. 2110.
No.
1
2
3
N
Range
S.D.
ML
41
39
38
3
38.0 – 39.3 – 41
1.52
MWI
107.3
94.9
105.3
94.9 – 102.5 – 107.3
6.65
HWI
97.6
87.2
100.0
87.2 – 94.9 – 100.0
6.80
MAI
24.9
28.3
27.5
24.9 – 26.9 – 28.3
1.77
ALI
79.3
77.0
77.5
77.0 – 77.9 – 79.3
1.20
AWI
19.5
18.0
18.4
18.0 – 18.6 – 19.5
0.77
WDI
31.5
27.5
30.4
27.5 – 29.8 – 31.5
2.06
SIn
8.0
5.9
5.8
5.8 – 6.6 – 8.0
1.24
HcAI
87.8
76.1
84.8
76.1 – 82.9 – 87.8
6.07
LLI
3.1
2.8
3.2
2.8 – 3.0 – 3.2
0.20
CLI
44.4
50.0
39.5
39.5 – 44.6 – 50.0
5.25
PLI
Arm formula
1.2.3.4
1.2.3.4
1.2.3.4
Web formula
CBDEA
BCDAE
CBDEA
Gills
6
6
6
TABLE 3. Measurements (in mm) of four females of Graneledone antarctica, new species, from ELTANIN Sta. 2110.
No.
4
5
6
7
Mantle length
45.0
41
39
25
Mantle width
43
37
36
23
Head width
40
32
34
23
Arm length
I
131
134
99
102
116
115
60
62
II
134
134
98
99
108
114
62
61
III
122
118
97
93
96
102
58
60
IV
198+
114
86
57+
96
101
59
56
Total length
177
143
157
88
Arm width
8.0
5.5
6.0
6.0
Web depth
A
32
25
28
17
B
41
42
30
32
32
37
18
-
C
42
43
35
33
32
37
21
20
D
37
38
32
32
32
31
19
17
E
31
20
22
17
Gills
6
6
6
6
+ = tip broken
Holotype: U.S. National Museum of Natural History 729679.
Type-locality: Ross Sea, Antarctica, ELTANIN Sta. 2110, 74°05.6'S, 175°05.2'W in 2341 m.
Discussion: Two other species assigned to Graneledone must be considered: G. challengeri (Berry, 1916) and ? G. setebos Robson, 1932.
G. antarctica superficially resembles G. challengeri in its bodily proportions. It differs from it in the structure of the funnel organ, hectocotylus, radula, and sculpture. The funnel organ in antarctica is formed of double oval pads slightly to moderately spilt anteriorly; in challengeri these organs are typically VV-shaped with narrow, pointed, anterior
TABLE 4. Indices of bodily proportions and counts of four females of Graneledone antarctica, new species from ELTANIN Sta. 2110.
No.
4
5
6
8
Range
S.D.
ML
45
41
39
25
25 – 37.5 – 45
8.69
MWI
95.6
90.2
92.3
92.0
90.2 – 92.5 – 95.6
2.25
HWI
88.9
78.1
87.1
92.0
78.1 – 80.5 – 92.0
5.97
MAI
33.6
40.2
33.6
40.3
33.6 – 36.9 – 40.3
3.83
ALI
75.7
71.3
73.9
70.5
70.5 – 72.8 – 75.7
2.39
AWI
17.8
13.4
15.3
24.0
13.4 – 17.6 – 24.0
4.61
WDI
32.1
34.3
31.9
33.9
31.9 – 33.1 – 34.3
1.22
limbs. In antarctica the ligula is a small and moderately well differentiated; in challengeri the ligula is well formed, deeply excavated, with sharply differentiated calamus. The radula of antarctica is highly variable but shows a general uniformity of teeth; in challengeri the radula is more typically octopodan. The sculpture of antarctica varies from challengeri in the more scattered, more widely separated tubercles, and the presence of 2 to 3 much larger tubercles over the eyes. The wide membrane on the ventral side of the arms in antarctica also seems distinctive.
There is no point of comparison with ? G. setebos for the reasons given in the general discussion.
The etymology of the name is self-evident.”
(Voss, 1976: 448-454)
