dcsimg

Description

provided by NMNH Antarctic Invertebrates

Metavargula currax Kornicker, new species

Figure 13

Metavargula species C, Kornicker, 1994, fig. 10hh,ii.

[Should be fig. 110hh, ii]

ETYMOLOGY.—From the Latin currax (swift).

HOLOTYPE.—NMV J35988, ovigerous female.

TYPE LOCALITY.—Slope 46. 42°00.20’S, 148°37.70’E, Tasmania, off Freycinet Peninsula; depth 720 m.

PARATYPE.—USNM 193857, ovigerous female on slide and in alcohol, in collection of the Museum of Victoria.

DISTRIBUTION.—Slope 46,720 m.

DESCRIPTION OF ADULT FEMALE.—Carapace similar in shape to that of M. calix.

Infold: In general, similar to that of M. calix except anteroventral infold with 2 or 3 long bristles rather than 4, and bulge at dorsal end of anterior edge of flange of caudal process broader.

Selvage: Similar to that of M. calix.

Carapace Size (length, height in mm): NMV J35988 (holotype), 4.8, 3.0; height 62% of length. USNM 193857, 5.2, 3.2; height 62% of length.

First and Second Antennae: Similar to those of M. calix.

Mandible: Coxale, basale, exopodite, and 1st and 3rd endopodial joints similar to those of M. calix. 2nd endopodial joint: Ventral margin differs from that of M. calix in having 2 single distal bristles and 1 pair of terminal bristles (medial slightly shorter but broader than lateral, with 7 spines along inner margin); dorsal margin with 17 or 18 bristles (5 long spinous, 2 or 3 medium length, and 10 short spinous medial).

Maxilla: Endite bristles not counted but appearing similar to those of M. spadix. Basale similar to that of M. calix. Exopodite similar to that of M. calix except both terminal bristles with long proximal hairs. 1st endopodial joint with alpha- and beta-bristles similar to those of M. calix; cutting tooth bilobed. 2nd endopodial joint with 4 a-bristles (2 anterior bare or with few spines, 2 posterior spinous), 3 pectinate b-bristles, 4 c-bristles (inner small bare, others stout pectinate), and 3 pectinate d-bristles (only outer bristle ringed). Main difference between maxillae of M. currax and M. calix is presence of 4 c-bristles on former and 3 on latter.

Fifth Limb: Protopodite and 1st and 2nd exopodial joints similar to those of M. calix. 3rd exopodial joint: Inner lobe with 1 proximal bristle with long proximal hairs and 2 or 3 terminal bristles (both limbs of holotype and 1 of USNM 193857 with 3 terminal bristles); outer lobe with 2 ringed bristles with long proximal hairs. 4th exopodial joint with 4 bristles (bare or with short marginal spines). 5th joint not separated from 4th by suture, with 2 bristles with short marginal spines; small spined process on comer near 4th joint 3rd-5th joints hirsute.

Sixth Limb: With 6 or 7 epipodial bristles; sclerotized boss proximal to bristles well developed on right limb of holotype, smaller on left limb. Endite I with 3 short medial bristles and 1 long terminal bristle; endite II with 3 or 4 medial and 2 terminal bristles; endites III and IV each with 3 terminal bristles (middle bristle shorter). End joint with 12 or 13 bristles with long proximal and short distal spines (except 1 small lateral bristle near anterior may have only short spines), then space and 3 bristles (anterior with long proximal and short distal spines, others plumose). Limb hirsute.

Seventh Limb: Holotype: One limb with 34 bristles (terminal group with 11 bristles on comb side and 9 on peg side; proximal group with 7 bristles on comb side and 7 on peg side). Other limb with 34 bristles (terminal group with 11 bristles on comb side and 9 on peg side; proximal group with 5 bristles on comb side and 9 on peg side). Each bristle with up to 8 bells. Comb with 9 or 10 slender ringed spinous teeth with recurved slightly bulbous tips. Single ringed peg with slightly bulbous tip opposite comb. USNM 193857: One limb with 33 bristles (terminal group with 11 bristles on comb side and 10 on peg side; proximal group with 5 bristles on comb side and 7 on peg side); other limb with 37 bristles (terminal group with 11 bristles on comb side and 10 on peg side; proximal group with 7 bristles on comb side and 9 on peg side). Each bristle with up to 7 bells. Comb with 10 or 11 spinous teeth opposite single peg with indistinct spines.

Furca: Similar to that of M. spadix.

Bellonci Organ: Cylindrical with small process at tip.

Eyes: Medial eye well developed, with brown pigmentation along center line. Lateral eye with brown pigment and about 3 indistinct ovals (ommatidia?).

Upper Lip: Tusks with low lateral projection along distal 2/3 bearing numerous small glandular openings.

Genitalia: Oval bearing round spermatophore on each side of body anterior to furca.

Anterior and Posterior of Body: Similar to those of M. calix.

Y-Sclerite: typical for subfamily.

Eggs: Holotype with 42 eggs in marsupium; length of typical egg 0.52 mm. USNM 193857 with 32 eggs in marsupium; length of typical egg 0.52 mm

COMPARISONS.—Metavargula currax differs from M. calyx mainly in having 2 single bristles rather than 1 on the ventral margin of the 2nd endopodial joint of the mandible. The comb of the 7th limb of M currax bears 9-11 teeth compared to 15 teeth on M. calix. and the maxilla bears 4 c -bristles compared to 3 on M. calix.”

(Kornicker & Poore, 1996, p.33-35)

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author
Kornicker & Poore, 1996, p.33-35
project
Smithsonian National Museum of Natural History - Antarctic Invertebrates

Comprehensive Description

provided by Smithsonian Contributions to Zoology
Metavargula currax Kornicker

Metavargula species C, Kornicker, 1994, fig. 10hh,ii.

ETYMOLOGY.—From the Latin currax (swift).

HOLOTYPE.—NMV J35988, ovigerous female.

TYPE LOCALITY.—Slope 46, 42°00.20′S, 148°37.70′E, Tasmania, off Freycinet Peninsula; depth 720 m.

PARATYPE.—USNM 193857, ovigerous female on slide and in alcohol, in collection of the Museum of Victoria.

DISTRIBUTION.—Slope 46, 720 m.

DESCRIPTION OF ADULT FEMALE.—Carapace similar in shape to that of M. calix (Figure 13a).

Infold: In general, similar to that of M. calix except anteroventral infold with 2 or 3 long bristles rather than 4 (Figure 13b), and bulge at dorsal end of anterior edge of flange of caudal process broader (Figure 13c).

Selvage: Similar to that of M. calix.

Carapace Size (length, height in mm): NMV J35988 (holotype), 4.8, 3.0; height 62% of length. USNM 193857, 5.2, 3.2; height 62% of length.

First and Second Antennae: Similar to those of M. calix.

Mandible: Coxale, basale, exopodite, and 1st and 3rd endopodial joints similar to those of M. calix. 2nd endopodial joint: Ventral margin differs from that of M. calix in having 2 single distal bristles and 1 pair of terminal bristles (medial slightly shorter but broader than lateral, with 7 spines along inner margin); dorsal margin with 17 or 18 bristles (5 long spinous, 2 or 3 medium length, and 10 short spinous medial).

Maxilla: Endite bristles not counted but appearing similar to those of M. spadix. Basale similar to that of M. calix. Exopodite similar to that of M. calix except both terminal bristles with long proximal hairs. 1st endopodial joint with alpha- and beta-bristles similar to those of M. calix; cutting tooth bilobed (Figure 13d). 2nd endopodial joint with 4 a-bristles (2 anterior bare or with few spines, 2 posterior spinous), 3 pectinate b-bristles, 4 c-bristles (inner small bare, others stout pectinate) (Figure 13e), and 3 pectinate d-bristles (only outer bristle ringed). Main difference between maxillae of M. currax and M. calix is presence of 4 c-bristles on former and 3 on latter.

Fifth Limb: Protopodite and 1st and 2nd exopodial joints similar to those of M. calix (c- and d-bristles shown in Figure 13f,g). 3rd exopodial joint: Inner lobe with 1 proximal bristle with long proximal hairs and 2 or 3 terminal bristles (both limbs of holotype and 1 of USNM 193857 with 3 terminal bristles); outer lobe with 2 ringed bristles with long proximal hairs. 4th exopodial joint with 4 bristles (bare or with short marginal spines). 5th joint not separated from 4th by suture, with 2 bristles with short marginal spines; small spined process on comer near 4th joint 3rd–5th joints hirsute.

Sixth Limb: With 6 or 7 epipodial bristles; sclerotized boss proximal to bristles well developed on right limb of holotype (Figure 13h), smaller on left limb. Endite I with 3 short medial bristles and 1 long terminal bristle; endite II with 3 or 4 medial and 2 terminal bristles; endites III and IV each with 3 terminal bristles (middle bristle shorter). End joint with 12 or 13 bristles with long proximal and short distal spines (except 1 small lateral bristle near anterior may have only short spines), then space and 3 bristles (anterior with long proximal and short distal spines, others plumose). Limb hirsute.

Seventh Limb: Holotype: One limb with 34 bristles (terminal group with 11 bristles on comb side and 9 on peg side; proximal group with 7 bristles on comb side and 7 on peg side). Other limb with 34 bristles (terminal group with 11 bristles on comb side and 9 on peg side; proximal group with 5 bristles on comb side and 9 on peg side). Each bristle with up to 8 bells. Comb with 9 or 10 slender ringed spinous teeth with recurved slightly bulbous tips. Single ringed peg with slightly bulbous tip opposite comb. USNM 193857: One limb with 33 bristles (terminal group with 11 bristles on comb side and 10 on peg side; proximal group with 5 bristles on comb side and 7 on peg side); other limb with 37 bristles (terminal group with 11 bristles on comb side and 10 on peg side; proximal group with 7 bristles on comb side and 9 on peg side). Each bristle with up to 7 bells. Comb with 10 or 11 spinous teeth opposite single peg with indistinct spines.

Furca: Similar to that of M. spadix.

Bellonci Organ (Figure 13i): Cylindrical with small process at tip.

Eyes: Medial eye well developed, with brown pigmentation along center line (Figure 13i). Lateral eye with brown pigment and about 3 indistinct ovals (ommatidia?) (Figure 13i).

Upper Lip (Figure 13j): Tusks with low lateral projection along distal bearing numerous small glandular openings.

Genitalia: Oval bearing round spermatophore on each side of body anterior to furca.

Anterior and Posterior of Body: Similar to those of M. calix.

Y-Sclerite: Typical for subfamily.

Eggs: Holotype with 42 eggs in marsupium (not all shown in Figure 13a); length of typical egg 0.52 mm. USNM 193857 with 32 eggs in marsupium; length of typical egg 0.52 mm.

COMPARISONS.—Metavargula currax differs from M. calix mainly in having 2 single bristles rather than 1 on the ventral margin of the 2nd endopodial joint of the mandible. The comb of the 7th limb of M. currax bears 9–11 teeth compared to 15 teeth on M. calix, and the maxilla bears 4 c-bristles compared to 3 on M. calix.
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cc-by-nc-sa-3.0
bibliographic citation
Kornicker, Louis S. and Poore, C. B. 1996. "Ostracoda (Myodocopina) of the SE Australian Continental Slope, Part 3." Smithsonian Contributions to Zoology. 1-186. https://doi.org/10.5479/si.00810282.573