“Philomedes pseudolofthousae, new species
Figures 45,46
ETYMOLOGY.—From the Greek Pseudos (lie) plus lofthousae; so named because the species closely resembles P. lofthousae Komicker, 1975.
HOLOTYPE.—1 partly dissected adult female in alcohol in collection of the Museum of Victoria.
TYPE LOCALITY.—Slope 69, 76 km south of Point Hicks, Victoria, 38°29.33'S, 149°19.98'E; depth 1840 m.
PARATYPES.—Slope 66: USNM 193976, 1 partly dissected adult female in alcohol. Slope 69: USNM 193946, 1 adult female on slide and in alcohol; 1 undissected adult female, 1 partly dissected A-l male, and 5 undissected juveniles, all in alcohol.
DISTRIBUTION.—Slope 66,2900 m. Slope 69,1840 m.
DESCRIPTION OF ADULT FEMALE.— Carapace with prominent rostrum with minute protuberance at tip, broad incisur, and truncate posterior.
Ornamentation: Carapace smooth with scattered single bristles more abundant along anterior and ventral margins; internal reticulations indistinctly visible with transmitted light.
Infold: Infold of rostrum of left valve of USNM 193946 with 26 bristles forming row; right valve with 5 additional bristles along dorsal edge; 1 small bristle on infold posterior to inner end of incisur; anteroventral infold with 14 striae proximal and parallel to narrow list, and 14 bristles along list; middle part of ventral list without bristles; list extending along posterior 1/3 of ventral infold and onto infold of caudal process, and with numerous bristles (anterior 6 bristles single, remaining bristles in groups of 1 to 5); infold of caudal process with 7 or 8 short bristles forming row between list and valve edge, and 4 small bristles along outer edge.
Selvage: Lamellar prolongation with marginal fringe present along anterior, ventral, and posterior margins, but absent, or very narrow, along posterior edge of caudal process; prolongation with typical segmentation along rostrum and incisur; prolongation along anteroventral margin with long proximal threads extending well past outer edge of prolongation.
Carapace Size (length, height in mm): Slope 69: holotype, 2.34, 1.47, height 63% of length; paratypes: 2.36, 1.60, height 68% of length; USNM 193946, 2.35, 1.56 height 66% of length. Slope 66: USNM 193976, 2.41, 1.62, height 67% of length.
First Antenna: 1st joint with long ventral spines. 2nd joint with ventral, dorsal, lateral, and medial rows of long spines and 5 or 6 bristles (both limbs of USNM 193946 with 6 bristles (2 ventral, 2 dorsal, 2 lateral); holotype similar except with only 5 bristles (only 1 dorsal bristle on left limb and 1 lateral bristle on right limb)) with long proximal and short distal spines. 3rd joint with row of medial spines and 3 spinous bristles (1 ventral, 2 dorsal). 4th joint with minute distal medial pore at midheight and 5 spinous bristles (4 ventral, 1 dorsal). Sensory bristle of 5th joint with 5 short marginal filaments and tip with 5 filaments. 6th joint fused to 5th; medial bristle about half length of bristle of 5th joint, with long proximal and short distal spines. 7th joint: a-bristle more than half length of bristle of 5th joint, with short marginal spines; b-bristle about 2/3 length of bristle of 5th joint, with 1 proximal and 4 terminal filaments; c -bristle about same length as bristle of 5th joint, with 5 marginal and 4 terminal filaments. 8th joint: d- and e-bristles same length as c-bristle, bare with blunt tips; f-bristle shorter than c-bristle, with 4 marginal and 5 terminal filaments; g-bristle same length as c-bristle, with 3 marginal and 5 terminal filaments.
Second Antenna: Protopodite with long spines along distal dorsal margin. Endopodite 2-jointed: 1st joint with 6 short bare bristles (5 proximal, 1 subterminal); 2nd joint elongate with 3 spinous ventral bristles (proximal long with long proximal and short distal spines, others shorter and with short spines) and recurved terminal bristle. Exopodite: 1st joint with short tubular medial terminal bristle; bristle of 2nd joint reaching well past 9th joint, with 14 ventral spines; bristles of joints 3-5 with ventral spines and no natatory hairs; bristles of joint 6-8 with natatory hairs (some bristles broken); 9th joint with 7 bristles (4 long with natatory hairs (some bristles broken), 3 short with small slender marginal spines); joints 2-8 with slender spines along distal edges; joints 2-7 with row of medial spines at midlength; slender basal spines on joints 7 and 8, possibly others (obscured).
Mandible: Coxale with long medial spines; endite with long proximal spines and teeth on bifurcate tip; small ringed bristle near base of endite. Basale: dorsal margin with 4 or 5 bristles (USNM 193946 with 5 bristles on both limbs; holotype and USNM 193976 with 4 on left limb and 5 on right), including 2 or 3 placed distal to midlength and 2 terminal; medial side with rows of spines and 6 proximal bristles (3 stout unringed pectinate, 3 slender ringed spinous) near ventral margin; ventral margin with 3 distal spinous bristles; lateral side near ventral margin with 5 spinous bristles. Exopodite about 3/4 length of dorsal margin of 1st endopodial joint, hirsute distally, with 2 subterminal bristles (proximal very slightly longer) with long proximal and short distal spines. 1st endopodial joint with 4 long ventral terminal spinous bristles and row of terminal spines on dorsal margin. 2nd endopodial joint: dorsal margin with proximal spines and 9 spinous bristles (3 in proximal group, 6 in distal group); ventral margin with 2 groups of spinous bristles, each with 3 bristles; medial surface with rows of spines. 2nd endopodial joint with 3 claws (dorsal claw about half length of longest claw; long medial claw slightly shorter than lateral claw; all claws with spines along middle of ventral margin) and 4 spinous bristles.
Maxilla: Endite I with 10 spinous bristles; endite II with 6 spinous bristles; endite III with 1 spinous proximal bristle and about 8 spinous terminal bristles. Coxale with plumose dorsal bristle. Basale with 4 bristles (2 dorsal, 1 medial, 1 ventral; on USNM 193946 1 dorsal bristle about half length of other; on holotype bristles of similar length (both long). Exopodite with 3 bristles (1 short proximal, 2 long terminal). 1st endopodial joint with dorsal spines, 1 long alpha-bristle with long proximal spines, and 4 shorter betabristles with few spines. 2nd endopodial joint with 3 stout unringed pectinate claws and about 5 ringed bristles.
Fifth Limb: 1 st exopodial joint with 2 long anterior bristles and 1 short spinous bristle at outer comer, main tooth with bilobed anterior tooth, 3 pectinate teeth, and 1 proximal bare tooth; ringed bristle with short spines present proximal to smooth tooth. 2nd exopodial joint with 2 protuberances on inner margin of large flat triangular tooth; small slender posterior plumose bristle near distal outer comer of tooth; posterior c-bristle obscured on USNM 193946. 3rd exopodial joint with 3 spinous bristles on inner lobe and 2 plumose bristles on
hirsute outer lobe. 4th and 5th exopodial joints fused, hirsute, with total of 6 spinous bristles.
Sixth Limb: With 3 short plumose epipodial bristles. Endite I with 3 spinous bristles (2 short medial, 1 long terminal); endite II with 4 spinous bristles (1 short medial, 3 long terminal); endite III with 9 or 10 spinous bristles (1 short medial, 8 or 9 long terminal); endite IV with 7 or 8 spinous bristles (1 short medial, 6 or 7 long terminal). End joint with 19 spinous bristles; limb hirsute.
Seventh Limb: Limb with 25 bristles: 20 in proximal group (13 or 14 on peg side, 11 or 12 on comb side), each with 4-6 bells (most with 5); and 5 in terminal group (3 on peg side, 2 on comb side), each with 4-7 bells. Terminus with comb of 15 alate teeth opposite 2 straight pegs with rounded tips.
Furca: Each lamella with 9 or 10 claws decreasing in length posteriorly along lamella but posterior 4 or 5 claws fairly similar in length; all claws with teeth along posterior edges; claw 1 also with row of stout medial teeth; hairs present on lamella medial to bases of claws and following posterior claw; right lamella anterior to left by width of base of claw 1 and with spines along anterior edge; 5th claw of illustrated left lamella aberrant in having bifurcate tip.
Bellonci Organ: Elongate with indistinct suture at midlength and rounded tip.
Eyes: Lateral eye small, unpigmented, with 2 ommatidia. Medial eye large with small area with brown pigment.
Upper Lip: Hirsute ventrally and with 2 small diaphanous processes at anterior tip.
Genitalia: Small amber-colored oval on each side of body anterior to furca.
Brush-like Organ: Organ comprising about 7 minute bristles on each side dorsal to genitalia.
Anterior of Body: With elongate tapering anterior process with knob-like tip.
Posterior of Body: With long hairs along ventral 1/3, and few rows of indistinct spines on rounded posterodorsal corner.
Y-Sclerite: Typical for genus.
Number of Eggs: USNM 193946 with about 8 unextruded eggs of similar size on each side of body near brush-like organ; length of longest egg 0.104 mm.
DESCRIPTION OF A-l MALE.—Posterodorsal comer and posterior of carapace more oblique than that of adult female.
Carapace Size (length, height in mm): Slope 69, 1.97, 1.19.
First Antenna: 2nd joint of specimen from Slope 69 with 4 bristles (2 dorsal, 1 ventral, 1 lateral) on each limb; 4th joint with 1 dorsal and 3 ventral bristles; limb otherwise similar to that of adult female, but filaments of bristles of 5th, 7th, and 8th joints not counted.
Second Antenna: Protopodite with long distal dorsal hairs. Endopodite 3-jointed: 1st joint short with 6 small bristles (5 proximal, 1 distal); 2nd joint elongate with 3 ventral bristles (proximal long with long proximal and short distal spines, others shorter); 3rd joint elongate with long proximal dorsal bristle and 2 small terminal bristles. Exopodite 9-jointed; all bristles fairly short, none with natatory hairs, most with spines; 9th joint with 6 bristles (4 stout, 2 small); joints 5-8, possibly others (obscured), with basal spines.
Mandible: Dorsal margin of basale of specimen from slope 69 with 5 bristles on each limb. Limb not studied in detail but appearing similar to that of adult female.
Maxilla: Basale with 2 long dorsal bristles. Remaining part of limb not studied.
Seventh Limb: Limb with 18 bristles: 13 in proximal group (6 on comb side, 7 on peg side), each with 3 or 4 bells; 5 in terminal group (2 on comb side, 3 on peg side), each with 2-5 bells; all bristles tapering distally (juvenile character). Terminus with comb of about 6 teeth opposite 2 straight pegs.
Furca: Each lamella with 10 claws; teeth of claws similar to those of adult female.
Bellonci Organ: Similar to that of adult female except without suture at midlength.
Eyes: Lateral eye fairly large with numerous minute ommatidia, unpigmented. Medial eye not examined.
Genitalia: Obscured, if present
Anterior of Body: Anterior process similar to that of adult female.
Posterior of Body: Similar to that of adult female Gong hairs on posterior edge and spines on posterodorsal comer).
Y-Sclerite: Similar to that of adult female.
COMPARISONS.—The only other known species of Philomedes having 5 or 6 bristles (including 2 ventral bristles) on the 2nd joint of the 1st antenna of the adult female is P. lofthousae Komicker, 1975:281. The maxilla of P. pseudolofthousae differs from mat of P. lofthousae in having 2 rather than 1 bristle on the dorsal margin of the basale. An A-l male of P. pseudolofthousae studied herein also has 2 dorsal bristles on the basale of the maxilla. Philomedes lofthousae was collected in the vicinity of the Kerguelen Islands at depths of 25-55 m (Komicker, 1975:289). Philomedes pseudolofthousae was collected on the southern Australian slope at a depth of 1840 m. The 2 species are closely related.
REMARKS CONCERNING Philomedes lofthousae,—A maxilla of an A-l female (length of empty carapace 2.15 mm, height 1.40 mm) paratype of P. lofthousae (USNM 139853) was examined and found to have 3 bristles on the basale (1 dorsal, 1 medial, 1 ventral); the ventral bristle was overlooked on the adult female described by Komicker (1975:285). In the diagnosis of the species Komicker (1975:283) incorrectly gave the number of dorsal bristles on the mandibular basale of the adult female as 6; it should have been 4 as stated in the description of the species (1975:285) and as shown in the illustration of the mandible (1975, fig. 172g).”
(Kornicker, 1994, p. 81-85)
