Taeniacanthus longicervis (Pillai 1963)

Taeniacanthus longicervis (Pillai, 1963)

Parataeniacanthus longicervis Pillai, 1963:120.—Cressey and Cressey, 1979:13.


MATERIAL EXAMINED.—From Saurida undosquamis (Richardson): 2 females from 16°16′N, 114°41′E (South China Sea); 3 females from 11°52′N, 92°49′E (AB Cruise 1); 3 females, 1 male, 1 immature female from 21°49′N, 68°55′E (AB Cruise 4B); 1 female, 1 male from 20°49′N, 69°41′E (AB Cruise 4B). From Saurida elongata (Tem- minck and Schlegel) (USNM 9450): 2 females from Hong Kong. (AB = R/V Anton Bruun.)

DESCRIPTION.—Female: Body as in Figure 38A. Total length 3.04 mm (2.21–3.80 mm) and greatest width 0.85 mm (0.62–1.02 mm) based on 10 specimens. Cephalothorax 790 × 940 μm (1 × w), comprising approximately 25% of total length. First pedigerous segment completely fused to cephalothorax. Thoracic segments bearing legs 2, 3, and 4 decreasing in width posteriorly. Genital complex 282 × 432 μm (l × w). Abdomen 4–segmented; segments from anterior to posterior 329 × 310 μm, 320 × 282 μm, 235 × 235 μm, and 254 × 207 μm (l × w); anal segment (Figure 38B) with 1 row of spinules on each side of anteroventral surface and 2 membranous flaps near insertion of each caudal ramus. Caudal ramus (Figure 38B) 166 × 67 μm (l × w), bearing 6 setae (2 outer and 1 dorsal naked).

Rostral area (Figure 38C) with circular, sclerotized, ventromedian part between bases of first antenna. First antenna (Figure 38D) 7-segmented; armature formula: 5, 15, 5, 3, 4, 2 + 1 aesthete, and 7 + 1 aesthete. Second antenna (Figures 38E, 39A) apparently 4-segmented; first 2 segments each with 1 naked distal seta; third segment with 2 pectinate processes (longer one with small naked seta at tip, shorter one with small rounded hyaline knob at midlength); terminal segment with 2 spines and 5 setae. Postantennal process (Figure 39B) with slender, curved, attenuate tine.

Labrum (Figure 39C) with spinulated posterior margin and bearing truncate medial process on ventral surface. Mandible (Figure 39D) with 2 unequal blades, each spinulated along 1 margin, and 1 bristled seta. Paragnath (Figure 39E) with patch of spinules at base and 1 row of smaller spinules at midlength. First maxilla (Figure 39F) a lobe bearing 5 naked setae and 1 small knob. Second maxilla (Figure 39G) 2-segmented; first segment robust bearing rounded process near distomedial corner; terminal segment armed as in figure. Maxilliped (Figure 39H–J) 3-segmented; first segment with distomedial seta; second segment robust, bearing 2 inner proximal setae, and covered with curved creases; terminal segment a claw with 2 basal setae and 8–10 teeth.

Legs 1–4 (Figures 40A–F, 41A,B) biramous. Spinal and setal formula as follows:

P1 coxa 0-1 basis 1-1 exopod 1-0; 9

endopod 0-1; 7 (2 greatly reduced)

P2 coxa 0-0 basis 1-0 exopod 1-0; 1-1; II, I, 5

endopod 0-1; 0-2; II, I, 3

P3 coxa 0-0 basis 1-0 exopod 1-0; 1-1; II, I, 5

endopod 0-1; 0-2, II, I, 2

P4 coxa 0-0 basis 1-0 exopod 1-0; 1-1; II, I, 5

endopod 0-1; 0-1; II, int.

Interpodal plate of leg 1 (Figure 40A) broad, somewhat triangular with spinules on posterior margin. Interpodal plates of legs 2 and 3 as in Figure 40B. Interpodal plate of leg 4 (Figure 40F) without ornamentation. Terminal segment of endopod of leg 1 (Figure 40A) with 2 outermost setae greatly reduced; second seta from lateral side superimposed on third seta. First exopod segment of leg 2 (Figure 40B) inflated. Segments of exopods of legs 3 (Figure 40C,D) and 4 (Figure 41A) protuberant with slightly crenulated margins; first segment with dorsal corrugated area. Endopod spines of legs 2–4 (Figures 40B,E, 41B) with single row of spinules on outer margins. Leg 5 (Figure 41C) with 2 segments; first segment small, bearing dorsolateral seta; second segment 177 × 129 μm (l × w), bearing 3 setae with 2 rows of bristles and 1 blunt spine with single row; setae and spine with spinules at bases. Leg 6 represented by 3 setae near egg sac attachment.

Male: Body as in Figure 41D. Total length 2.91–2.94 mm and greatest width 0.73–0.76 mm based on 2 specimens. Cephalothorax 602 × 790 μm (l × w), comprising about 20% of total body length. Genital complex (Figure 41E) wider than long 263 × 320 μm (l × w), Abdomen (Figure 41D) 4-segmented; segments from anterior to posterior, 282 × 263 μm, 273 × 244 μm, 216 × 207 μm, and 216 × 169 μm (l × w). Caudal ramus similar to that of female, but measuring 143 × 48 μm (l × w).

Maxilliped (Figure 41F) 4-segmented; first segment with 1 naked seta; second segment (corpus) with 2 naked setae and a row of large denticles; third segment small and unornamented; terminal segment a curved claw bearing 2 setae near base and approximately 15 teeth. All other appendages as in female.

Taeniacanthus longicervis (Pillai, 1963)

Parataeniacanthus longicervis Pillai, 1963:120.—Cressey and Cressey, 1979:13.


MATERIAL EXAMINED.—From Saurida undosquamis (Richardson): 2 females from 16°16′N, 114°41′E (South China Sea); 3 females from 11°52′N, 92°49′E (AB Cruise 1); 3 females, 1 male, 1 immature female from 21°49′N, 68°55′E (AB Cruise 4B); 1 female, 1 male from 20°49′N, 69°41′E (AB Cruise 4B). From Saurida elongata (Temminck and Schlegel) (USNM 9450): 2 females from Hong Kong. (AB = R/V Anton Bruun.)

DESCRIPTION.—Female: Body as in Figure 38A. Total length 3.04 mm (2.21–3.80 mm) and greatest width 0.85 mm (0.62–1.02 mm) based on 10 specimens. Cephalothorax 790 × 940 μm (1 × w), comprising approximately 25% of total length. First pedigerous segment completely fused to cephalothorax. Thoracic segments bearing legs 2, 3, and 4 decreasing in width posteriorly. Genital complex 282 × 432 μm (l × w). Abdomen 4–segmented; segments from anterior to posterior 329 × 310 μm, 320 × 282 μm, 235 × 235 μm, and 254 × 207 μm (l × w); anal segment (Figure 38B) with 1 row of spinules on each side of anteroventral surface and 2 membranous flaps near insertion of each caudal ramus. Caudal ramus (Figure 38B) 166 × 67 μm (l × w), bearing 6 setae (2 outer and 1 dorsal naked).

Rostral area (Figure 38C) with circular, sclerotized, ventromedian part between bases of first antenna. First antenna (Figure 38D) 7-segmented; armature formula: 5, 15, 5, 3, 4, 2 + 1 aesthete, and 7 + 1 aesthete. Second antenna (Figures 38E, 39A) apparently 4-segmented; first 2 segments each with 1 naked distal seta; third segment with 2 pectinate processes (longer one with small naked seta at tip, shorter one with small rounded hyaline knob at midlength); terminal segment with 2 spines and 5 setae. Postantennal process (Figure 39B) with slender, curved, attenuate tine.

Labrum (Figure 39C) with spinulated posterior margin and bearing truncate medial process on ventral surface. Mandible (Figure 39D) with 2 unequal blades, each spinulated along 1 margin, and 1 bristled seta. Paragnath (Figure 39E) with patch of spinules at base and 1 row of smaller spinules at midlength. First maxilla (Figure 39F) a lobe bearing 5 naked setae and 1 small knob. Second maxilla (Figure 39G) 2-segmented; first segment robust bearing rounded process near distomedial corner; terminal segment armed as in figure. Maxilliped (Figure 39H–J) 3-segmented; first segment with distomedial seta; second segment robust, bearing 2 inner proximal setae, and covered with curved creases; terminal segment a claw with 2 basal setae and 8–10 teeth.

Legs 1–4 (Figures 40A–F, 41A,B) biramous. Spinal and setal formula as follows:

P1 coxa 0-1 basis 1-1 exopod 1-0; 9

endopod 0-1; 7 (2 greatly reduced)

P2 coxa 0-0 basis 1-0 exopod 1-0; 1-1; II, I, 5

endopod 0-1; 0-2; II, I, 3

P3 coxa 0-0 basis 1-0 exopod 1-0; 1-1; II, I, 5

endopod 0-1; 0-2, II, I, 2

P4 coxa 0-0 basis 1-0 exopod 1-0; 1-1; II, I, 5

endopod 0-1; 0-1; II, int.

Interpodal plate of leg 1 (Figure 40A) broad, somewhat triangular with spinules on posterior margin. Interpodal plates of legs 2 and 3 as in Figure 40B. Interpodal plate of leg 4 (Figure 40F) without ornamentation. Terminal segment of endopod of leg 1 (Figure 40A) with 2 outermost setae greatly reduced; second seta from lateral side superimposed on third seta. First exopod segment of leg 2 (Figure 40B) inflated. Segments of exopods of legs 3 (Figure 40C,D) and 4 (Figure 41A) protuberant with slightly crenulated margins; first segment with dorsal corrugated area. Endopod spines of legs 2–4 (Figures 40B,E, 41B) with single row of spinules on outer margins. Leg 5 (Figure 41C) with 2 segments; first segment small, bearing dorsolateral seta; second segment 177 × 129 μm (l × w), bearing 3 setae with 2 rows of bristles and 1 blunt spine with single row; setae and spine with spinules at bases. Leg 6 represented by 3 setae near egg sac attachment.

Male: Body as in Figure 41D. Total length 2.91–2.94 mm and greatest width 0.73–0.76 mm based on 2 specimens. Cephalothorax 602 × 790 μm (l × w), comprising about 20% of total body length. Genital complex (Figure 41E) wider than long 263 × 320 μm (l × w), Abdomen (Figure 41D) 4-segmented; segments from anterior to posterior, 282 × 263 μm, 273 × 244 μm, 216 × 207 μm, and 216 × 169 μm (l × w). Caudal ramus similar to that of female, but measuring 143 × 48 μm (l × w).

Maxilliped (Figure 41F) 4-segmented; first segment with 1 naked seta; second segment (corpus) with 2 naked setae and a row of large denticles; third segment small and unornamented; terminal segment a curved claw bearing 2 setae near base and approximately 15 teeth. All other appendages as in female.

Parataeniacanthus longicervis Pillai, 1963

MATERIAL EXAMINED.—13 1 from the gills of Saurida undosquamis (Richardson) from the following localities: R/V Anton Bruun, Cruise 4B, Station 209A (20°49′N, 60°41′E) and Station 216A (21°49′N, 68°55′E), Cruise 1, Station 28A (11°52′N, 92°49′E), R/V Cape St Mary, Cruise 20, South China Sea (16°6′N, 114°41′E); 2 from the gills of Saurida elongata (Temminck and Schlegel) from Hong Kong.

Female: The female of this species was described by Pillai (1963) and only a few points will be added here to that description. Illustrations of diagnostic features are included so that the reader can identify material of this species without reference to the original description. Body form as in Figure 25a. Total length 4.07 mm. Greatest width 1.16 mm (measured at widest part of cephalon). Caudal rami (Figure 25c) twice as long as wide (248 × 118 μm). Oral area typically taeniacanthid. Maxilliped (Figure 25d) with variable number of teeth (6–9) on prominent claw.

Legs 1–4 biramous, rami 3–segmented. Leg 2 (Figure 25e) as in Pillai except 3 outer spines of endopod fringed on outer edge. Leg 3 (Figure 25f) as in Pillai except very small spinules near base of exopod distalmost outer spine (Pillai notes these on leg 4 only). Leg 4 (Figure 25g) as in Pillai with pair of small spinules near base of each outer spine on segments 2 and 3. Leg 5 (Figures 26a) lamelliform, innermost seta (short claw of Pillai) heavily sclerotized, truncate, spinelike. Leg 6 (see Figure 25b) represented by 3 short setae at area of egg sac attachment.

Male: Body form as in Figure 26b. Total length 3.18 mm. Greatest width 0.83 mm (measured at widest part of cephalon). Cephalon 0.64 mm long. Genital segment slightly wider than long (354 × 324 μm). Abdomen 4–segmented, each segment wider than long, measuring 354 × 277 μm, 313 × 248 μm, 248 × 218 μm, and 195 × 177 μm respectively. Caudal ramus nearly 3 times as long as wide (153 × 57μm), longest seta 678 μm. Appendages as in female except maxilliped (Figure 26d). Maxilliped basal segment with row of rounded teeth, claw with distal double row of teeth.

MATERIAL EXAMINED.—13 1 from gills of 12 Saurida elongata (Temminck and Schlegel) (USNM 136243) collected in the Philippines (1909 Albatross collection), 1 from the gills of Saurida gracilis (Quoy and Gaimard), 2 from the gills of Saurida longimanus Norman (USNM 136050 and 136213) also from same collection area as above, 1 from the gills of Saurida undosquamis (Richardson) collected during Cruise 1 of the R/V Anton Bruun in the Andaman Sea (9°13′N, 97°5′E), 3 March 1963.

Female: The female of this species was adequately described by the authors and no further description will be included here except where differences were noted or to enable the reader to identify this parasite without reference to the original description. Body form as in Figure 27a. First antenna 7–segmented. Maxilliped (Figure 27b) basal segment with 2 setae on inner margin (Y and Y note only 1), 2 short setae near base of claw, claw bifid at tip. Leg 2 (Figure 27c) as in Y and Y but comblike folds on outer margins of exopod segments and last 2 endopod segments seen as sclerotized areas on specimens recorded above. Legs 3 and 4 as in Figures 27d and 27e.

Male: Body form as in Figure 27f. Total length 0.84 mm, greatest width 0.34 mm (measured at widest part of cephalon). Cephalon somewhat wider than long (336 × 271 μm). Thoracic segment bearing leg 1 fused with cephalon. Thoracic segments bearing legs 2–5 free. Genital segment (Figure 28a) wider than long (153 × 106 μm). Abdomen (see Figure 27f) 3–segmented, each segment wider than long and measuring 83 × 41 μm, 77 × 35 μm, and 71 × 41 μm respectively. Caudal rami about twice as long as wide (47 × 20 μm), longest seta 212 μm.

Oral area and mouthparts as in female. Maxilliped (Figure 28b) basal segment with prominent seta near inner mid-margin, 2 rows of knoblike spinules on distal two-thirds with a short row of pointed spinules proximal to knobs; claw with a basal seta and toothed as in the figure.

Leg 1 as in female. Legs 2–4 biramous, rami 3–segmented. Leg 2 (Figure 28c) exopod first segment with slender spine on outer distal corner, second segment with inner plumose seta and outer distal spine, last segment with 3 outer spines and 5 terminal to inner setae; endopod first segment with inner plumose seta, second segment with 2 inner setae, last segment with 3 stout, toothed, outer spines and 3 inner setae. Leg 3 (Figure 28d) exopod as in leg 2 except one less spine and one additional seta on last segment, endopod as in leg 2 except terminalmost toothed spine of last segment much longer than other 2, and 1 less inner seta. Leg 4 (Figure 28e) exopod as in leg 3; endopod first and second segments each with an inner seta, last segment with 2 toothed spines and 1 terminal seta. Leg 5 (Figure 28f) basipod with an outer seta; free segment with one outer lateral and 3 terminal setae, all setae of about equal length (inner 2 slightly longer than outer 2). Leg 6 absent.

Trivandrum, India; Hong Kong; South China Sea