Lowrya kornickeri, Parker, 1998

Parker, A. R., 1998, A new genus and two new species of Cypridinidae (Crustacea: Ostracoda: Myodocopina) from Australia, Records of the Australian Museum 50 (1), pp. 1-17 : 9-16

Lowrya kornickeri n.sp.

Figs 5-7

Type locality. Collected from east of Grotto Point , ~ort Jackson, NSW, Australia (33°49.05'S 151°15.92'E); baited trap set overnight at 11 m depth. Collected by P. Berents, A. R. Parker, K.B. Attwood and A. Murray on M.Y. Sula, 25-26 November 1993. In addition to Lowrya kornickeri unidentified cirolanid isopods and lysianassoid amphipods were caught. Only a small (representative) proportion of this trap sample was made available (this study was not the primary purpose of the trapping), therefore relative abundances are unknown. No adult females are known .

Type material. HOLOTYPE: AM P45463, adult male . PARATYPES: AM P45465, adult male ; AM P45464, juvenile (A-I) female ; AM P42244, adult male ; BMNH 1995 :1603, adult male (undissected) ; NMNH, adult male (undissected).

Description of adult male characters

COLOUR OFLIVINGOSTRACODS. Beige with aredareaabove the incisure when viewed from certain directions.

CARAPACE. Length = 1.24 mm, height = 0.82 mm; length/height = 1.51. Range of length = 1.22-1.28 mm (number of specimens examined ::;: 4).

Shape ( Fig. 6A ): rectangular oval, very slightly protruding keel; margins slightly rounded, poster.odorsal margin more steeply sloped than anterodorsal margm. Keel joined to curved posterior margin of valve by smooth convex curve; dorsal edge ofkeel slightly below midheight of valve; dorsal edge of incisure slightly overlapping ventral edge at inner end, prominent line on outer surface of valve curving from inner dorsal edge of incisure to anteriormargin of valve (ventral to incisure). Tipofrostrum rounded, with few small anterior bumps.

Valve surface: smooth at low magnification, but with faint scale-like pattern visible on anterior margins with light microscope at lOOx; setae on valve 獵牦慾攠 me~ium sized and scattered evenly; 9 muscle scars, formmg a CIrcle.

Infold ( Fig. 6B ): infold posterior to rostrum with row of 8 setae, double type, at an angle to valve margin, all dorsal to incisure; no setae anterior orposterior to carapace infold row. Dorsal edge of incisure with 4 single setae. Dorsal to dorsal inner corner of incisure with 1 double seta, at an angle with incisure margin. Sclerotized ridge (list) dorsal to incisure at an angle with incisure margin; sclerotization strong, causing red colouration from certain directions (after preservation) of dorsal incisure margin. Anteroventral infold, near inner corner of incisure, with 5 double setae (2 medium length, 3 short); posterior edge of carapace infold without setae. Infold parallel ~o anteroventral/ventral margin with 21 double setae; 3 m the region ventral to incisure; diminishing in length posteriorly; no setae anterior or posterior to anteroventral! ventral row. List becomes broader in vicinity of keel, forming a shallowly curved wide smooth ridge; keel infold simple. Ridge of keel unornamented except for minute short setae or papillae emerging from unrimmed pores, without setae; list of left valve without dorsal knob, and without processes. Right valve with posterior margin of keel without setae, with few papillae emerging from pores; dorsal margin of keel without process.

Lamellar prolongation of selvage: medium width along rostrum; very broad and striated along lower margin of incisure; narrower along ventral margin; terminating anteroventrally. Coelotrichs (evaginationJ"hair" sensillae; Parker, submitted) absent.

FIRST ANTENNA ( Fig. 6 G-K). First article bare. Second article: many medial spines forming rows, and spines on ventral and dorsal margins. Third article: short, without medial spines; with ventral seta of approximately equal to length of dorsal seta, positioned distally; 1 dorsal seta at base of article. Fourth article: 1 dorsal seta, of approximately equal length to dorsal seta of 3rd article; 1 ventral setae, positioned terminally, shorter than ventral seta of 3rd article; setae of 3rd and 4th articles ringed with short spinules. Fifth article: s-seta (formally the sensory seta of the fifth article; Parker, 1995, 1998) with 7 long proximal halophores (setules on the first antennae; Parker, 1995, 1998), some with proximal spinules; distally 2 nonterminal halophores, more slender and shorter (note that all halophores are generally short for Cypridinidae ). Sixth article: short, bare and ringed medial seta near dorsal margin. Seventh article: a-seta medium length, stout and ringed with few distal spinules; b-seta short, with basal setule with bulbous base, large proximal "sucker" (transparent) and small distal "sucker", without nonterminal halophores, additionally 2 setules present, each bearing 8-9 small "suckers", small process just proximal to most proximal "suckers" absent; c-seta long and ringed with bulbous base with large basal setule with sub-terminal process, and additional cup-shaped basal process from which a very large "sucker" (diameter> width of each of the distal five articles; transparent) arises, with 7 short and slender non-terminal halophores, most proximal halophore with few short spinules, additionally 2 proximal setules present, each bearing 8 small "suckers", small process proximal to most proximal "sucker" absent. Small "suckers" on the non-basal setules of the b- and c-setae bear widened, almost cone-shaped, shafts. Eighth article (very reduced or absent): d- and e-setae (including terminal halophores) longer than b-seta, bare and filamentous; fseta shorter than c-seta, with 8 short non-terminal halophores, most with small proximal spinules; g-seta shorter than c-seta and longer than f-seta, with 9 short nonterminal halophores, some with small proximal spinules. Bifurcate tips (2 terminal halophores) present on C-, f-, g­ and s-setae.

SECOND ANTENNA. Protopodite: long, bare seta. Endopodite ( Fig. 6F ): 3 articles. First article: 3 proximal setae; 2 short, 1 long, and no distal setae. Second article: elongate, with terminal long bare seta. Third article: longer than 2nd article and narrow; terminal seta long and unringed. Exopodite ( Fig. 6F ): second article: bearing seta with tip reaching to about 8th article, bearing 7 ventral robust spinules, most proximal spinule is similar size to others, no dorsal spinules; medium-short thin spine on ventral margin of article. Articles 3-8: with basal robust setae becoming longer distally; natatory setae with many fine setules, broad setules present on seta of 3rd article only. Ninth article: lateral robust seta of similar length to that of 8th article; 2 setae, both long with many fine setules.

MANDIBLE ( Fig. 7A ). Coxal endite: spinous; seta near base short, ringed and bare; 2 terminal setae, unringed and bare. Setae on ventral margin of basis: longest medial aseta short-medium length, with short distal spinules, about 3 times longerthan shortest seta; shortesta-seta bare; lateral b-seta short and bare, positioned very close to a-setae; longest c-seta long and bare; shortest c-seta short and bare; longest d-seta much longer than basis, with rings of long spinules; shortest d-seta much less than 0.5 times length of basis, and bare; space between c- and d-setae much larger than space between c-setae. Distal part of dorsal margin of basis: 3 setae; 1 more proximal seta, medium length and bare; 2 subterminal setae, subequal in length, with short spinules. Exopodite: similar length as 1st endopodial article; medial surface wrinkled; dorsal process hirsute, extending to a pointed tip; with 2 ventral mediumbroad setae, longest with short spinules. Endopodite: First endopodial article: 3 ventral setae; a-seta absent, b-seta medium length with spinules, c-seta long with spinules, d-seta long with rings oflong spinules. Second endopodial article: long, very thin, and slightly tapered; spines (in rows) onmedial surface are long and straight; dorsalmargin with 11 setae; 1 a-, 1 b-, 1 C-, 2 d-setae; c-seta longest; dsetae long with short spinules; 5 dorsomedial shorter setae (1 short, stout and unringed with long stout spinules); 1 seta distal to d-setae; ventral margin with few long spines and3 setae proximal to finger. Finger setaabout 60% length of finger; finger long, slender with wide base, curved with pointed tip and unringed. Terminal article: with 3 claws; claws all similarly curved and of approximately equal length; longest claw longer than finger; DM (dorsomedial) claw shortest and thinnest, tapered, with an almost pointed tip, bearing 5 spinules of medium length; VM (ventromedial) claw midsize, proximally stout, distally tapered, with rounded tip, bearing 12 spinules (6 medium length and proximal, 6 long and more distal); VLat (ventrolateral) claw slightly longer than VM claw, proximally stout, distally tapered, with a rounded tip, bearing 12 spinules (6 medium length and proximal, 6 long and more distal); 4 setae; ventromedial a-seta short, tapered, with an almost pointed tip; ventrolateral b-seta very long, almost bulbous proximally, distally tapered, with unevenly curved tip, bearing many short spinules; ventromedial c-seta medium length, tapered, with rounded tip; dorsolateral d-seta long, tapered, with almost pointed tip; b-seta longest; a-seta shortest.

FOURTH LIMB ( Fig. 7B,C ). Endite I with at least 6 setae; endite Il with 5 setae; endite III with 5 setae; trifid tips present on a few endite setae. Coxa: long dorsal seta with many setules. Basis: no lateral setae, 3 medial setae. Exopodite: bare; 1 proximal seta, long with many setules; 2 terminal setae, long with many setules. Endopodite: first endopodial article: approximately rectangular, uniformly spinous; cutting tooth large, with 2 squarish cusps, partial suture or cutting edge separating proximal part from rest of cutting tooth; 1 a-seta (aI), very long withmany setules; 2 ~-setae: 縲⵳整愠 medium length and bare, 縳⵳整愠 very long and denticulate. Second endopodial article: much narrower than 1st article; 4 a-setae; broad with widened bases, medium long with proximal spinules, ringed throughout most oflength; 3 b-setae; b I-seta medium width with widened base, long, ringed throughout most oflength, with 7 long medium-broad denticles, present proximally, and about 9 smaller distal spinules; b2-seta medium width with a widened base, medium length, ringed throughout most of length, with 6 broad denticles of medium length and present centrally; b3-seta (most posterior) claw-like, medium length, unringed, with 2 long, broad denticles, present centrally; 3 c-setae; cl-seta (most anterior) very thin, short and bare, ringed throughout most of length; c2- seta medium width with widened base, medium length, ringed throughout most of length, with 16 proximal broad denticles, longer proximally; c3-seta broad, long, ringed throughout most of length, with 15 long, broad denticles, present distally; 3 d-setae; dl-seta claw-like, mediumlength, unringed, with 6 long, broad denticles, present centrally; d2- seta claw-like, long, unringed, with 9 long, broad denticles, present centrally; d3-seta medium width with widened base, very long, distally ringed, with 35 medium-broad denticles, medium length proximally, decreasing in length distally, present along most of setal length.

FIFTH LIMB ( Fig. 7D ). 38 epipodial setae. Protopodite: anterior distal tooth with rounded tip. Endite I with 6 setae; endite Il with 6 setae; endite III with 7 setae. First exopodial article: posterior row of 6 denticular teeth; tooth 1 (smallest, most posterior) with 5 denticles, tooth 2 with 8 denticles, tooth 3 with 8 denticles, tooth 4 with 9 denticles, tooth 5 with 9 denticles, tooth 6 with 10 denticles; peg large, triangular; peg-seta medium length, stout, with very long, thin proximal spinules, peg-seta shorter than longest tooth; anterior side with row of 3 setae; 1st-seta (inner) short, thin with broadened base, and with very long, thin proximal spinules and long, broad distal spinules; 2ndseta very long, medium width with broadened base, very long, thin proximal spinules and long and broad distal spinules; 3rd-seta very long, medium width with broadened base and distal spinules; additionally 1 proximal anterior bare seta, very short, medium width with broadened base, close to protopodite. Second exopodial article: 4 a-setae, claw-like and coarsely denticulate; 5 b-setae, medium-long to very long, ringed, posterior row of 3 b'-setae, anterior row of 2 b"-setae; posterior c-seta unringed and bare; anterior d-seta distally ringed, with very long, thin proximal spinules. Inner lobe of third exopodial article with 3 setae; most proximal seta short, unringed, with distal spinules; subterminal seta long, ringed and bare; terminal seta medium-long, distally ringed, with distal spinules. Outer lobe of 3rd exopodial article: hirsute, 2 medium-broad setae; outer seta medium-long, distally ringed, with long thin proximal spinules and short thin distal spinules along outer margin only. Fourth andfifth exopodial articles fused and hirsute. Fifth article: 2 setae, subequal in length, ringed, with many short setules; terminal process large with long spines. Fourth article: 1 seta.

SIXTH LIMB ( Fig. 7F ). 3 bare and ringed setae in place of epipodite. EndUes with medial setae, separated from each other and rest of limb by sutures or grooves (except endites I and II, which are fused to rest of limb). Endite setae: 1= 3; 1 very long, distally ringed, with long setules; 2 very short, medium width, ringed, with long setules and without spinules; II = 5; 2 long, distally ringed, with long central setules and short distal spinules; 3 medium short, medium width with broad base, ringed, with long setules; longest with short distal spinules; III = 3; 2 long, distally ringed, with long central setules and with short distal spinules; 1 medium short, medium width, ringed, without setules and with short spinules; IV = 2, 1 very long, ringed, with long central setules and with short distal spinules; 1 short seta, medium long, thin with broad base, distally ringed, with long central setules and without spinules. Terminal article: approximately square shaped, basally separated by suture or groove from rest of limb; medial surface hirsute; lateral surface with rows of long spines; 5 anterior ventral terminal setae, with broad base abruptly constricting to narrow distal width, distally ringed, with long central setules and long distal spinules, reducing evenly in length from most anterior seta to most posterior, with bases on margin of article; gap posterior to anterior ventral terminal setae medium length, including rounded corner, gap = about 20% ventral length of terminal article, followed by 3 ringed posterior setae, some with bases on edge of article, some with bases set backfrom edge, longest is posterior, most anterior setae long, with broad base abruptly constricting to a narrow distal width, with long central setules and long distal spinules.

SEVENTH LIMB ( Fig. 7G ). Total of 10 setae. Comb side: 1 nonterminal seta, 4 terminal setae; minimum number of bells on setae = 4, maximum number ofbells on setae = 7. Peg side: 2 nonterminal setae, 3 terminal setae; minimum number of bells on setae = 4, maximum number of bells on setae = 6. Comb: 3 long teeth on each side, long teeth long, coarsely denticulate, with pointed tips, central long tooth longer than others; 2 short teeth on each side, short teeth medium long, with square tips, and deep grooves. Peg: long, slightly curved, very narrow; tip of peg similar width to centre of peg, and with many points; base of peg recessed from outer limb edge.

COPULATORY "LIMB" ( Fig. 7E ). First article: Y-sclerite prominent; strut present so that sclerite forms an irregular rectangular loop; loop broader distally;finger sclerite broad proximally, becoming narrow distally, forming a continuous section along inner margin of inner lobe, terminating near base of inner lobe. Inner lobe: elongate withrounded tip. Finger branch and setal branch separated by a deep terminal cleft. Finger branch: tip with stout spines; terminal and cleft region bare. Setal branch: external surface with 2 bare, ringed setae. Outer lobe: thumb sclerite forming edge of a triangle with an extended tip; thumb small and bare, located proximally on thumb sclerite, near hood; 2 bare, ringed setae located proximal to tip of thumb sclerite. Hood: dorsoventral length medium long; distally triangular becoming a finger-like lobe; anterior peak short; tip ofhood complete, with few minute scales or spines; hood extends almost entirely over inner lobe. Central lobe: width approximately equal to length; length = about 50% of that of inner lobe; 3 terminal ringed and setae with many spinules.

FuRCA ( Fig. 6C ). Left lamella with 9 claws, right lamella with 9 claws; claws 2 and 4 fused to lamella; claw 3 longer but thinner than claw 4; claw 1 long and medium wide;

claw 4 exceptionally broad; claw 5 short and broad; anterior claws short and broad; claws generally increasing in size posteriorly; claws generally slightly curved; all claws with spinules; distal medialrobust setules of most posterior claw broad; lamellae with concave posterior part of ventral margin, leading to an anterior ventral hump; left lamella bare, right lamella with medial long thin setae near distal ventral margin.

ANTERIOR OF BODY ( Fig. 6E ). Bellonci organ: (nonextended) is trapezoid (terminal margin longer than basal margin); length (non-extended) = 0.03 mm; width greater than length; tip (extended) bluntly rounded; without pigment.

Eyes: medial eye ( Fig. 6E ) large, length = 0.06 mm; pigmented. Lateral eye ( Fig. 6E ): very large, length = 0.27 mm; about 10 times size of medial eye; broadest dorsally; with at least 16 ommatidia (7 large, of approximately equal size; 9 small, of approximately equal size), largest ommatidia located dorsally; ommatidia light amber in transmitted light, matrix between ommatidia maroon in transmitted light.

Upper lip ( Fig. 6E ): pigmented. Anterior: single undivided process directed anteroventrally; ventral field of process pear-shaped, with about 16 large valves, arranged in about 3-5 anterior-posterior rows on a single plane; anterior process bare. Posterior: with very fine setae posteriorly. Tusks: short, consistently medium width; each with 2 valves, valves medium sized, forming a step-like profile of posterior tusk margin; tusks without setae or spines; spurs on tusks absent.

Frontal knob ( Fig. 6E ): large, rounded, width less than length; no projections ventral to frontal knob.

POSTERIOR OF BODY. Dorsal folds: absent. Y-sclerite: ventral branch <50% length of dorsal branch.

Description of juvenile (A-I) female characters.

Most characters common to both sexes have been omitted from the following description.

CARAPACE (Fig. SA). Length = 1.14 mm, height = 0.70 mm; lengthlheight = 1.63.

FIRST ANTENNA. Without "suckers" and basal setules of b- and c-setae; all halophores without spinules.

MANDIBLE. All setae generally with less spinules than male. Second endopodial article: dorsal margin with 7 bare setae; 1 a-, 1 b-, 2 shorter-, 1 C-, 2 d-setae (no setae distal to d-setae). Third endopodial article: c-seta of left limb curves in opposite direction to claws and b- and d-setae (probable artifact of slide preparation); c-seta of right limb similar to that of the male.

SIXTH LIMB. Terminal article: row of 4 anteroventral setae.

SEVENTH LIMB. Total of 8 setae. Comb side: without non-terminal setae; 3 terminal setae.

FURCA ( Fig. 8B ). Left lamella with 7 claws, right lamella with 8 claws; claws 2 and 4 proximally broader than in male; large medial robust setae of claw 1 (most posterior claw) present along almost complete length of claw; lamellae irregularly shaped, with very prominent hump midway along ventral margin.

ANTERIOR OF BODY. Lateral eye ( Fig. 8C ): large, length = 0.27 mm; broadest centrally (dorsal side similar size to ventral side); with at least 16 equally sized ommatidia.

Etymology. This species is named in honour of Louis S. Kornicker,myodocopidostracodexpert, whohasdescribed a large proportion of the known myodocopines, and taught the authorimportanttechniques forworking with ostracods.

Figures

Fig. 6. Lowrya kornickeri adult male (AM P45463). A, whole animal, lateral view. B, anterior of left carapace valve, medial view. C, left furcal lamella, lateral view. D, central adductor muscle scars of right carapace valve, medial view. E, anterior of body, limbs removed, showing medial eye (m.e.), lateral eye (l.e.), Bellonci organ (b.o.), frontal knob (f.k.), and upper lip (u.l.) including left tusk (t.), areas of maroon pigmentation shaded. F, endopodite (dashed) and exopodite of left 2nd antenna, lateral view. G, basal setule of b-seta of right 1st antenna, bearing 2 "suckers", medial view. H, terminal articles of left 1st antenna, s-seta not illustrated, 8th article not visible, lateral view. H (i), proximal section of 7th most proximal halophore of the f-seta of the left 1st antenna, lateral view. I, proximal halophores arising from shaft of s-seta of right 1st antenna, medial view. J, right 1st antenna, medial view. K, 2nd most proximal setule of the c-seta of the left 1st antenna, showing "suckers", lateral view. L, distal part of 2nd most proximal setule of the b-seta of the left 1st antenna, showing "suckers", dorsolateral view.

Fig. 7. Lowrya kornickeri adult male (AM P45463). A, right mandible, medial view. B, left 4th limb, showing some terminal endopodial setae, lateral view. C, terminal endopodial setae of right 4th limb excluded from B, medial view. D, terminal section of exopodite of right 5th limb, anterior view (the spines of many setae are longer than appear in this illustration, due to the angle of observation). E, left copulatory "limb", dorsal view. F, right 6th limb, lateral view. G, terminal section of 7th limb.

Fig. 8. Lowrya kornickeri juvenile (A-I) female (AM P45464). A, right carapace valve, lateral view. B, left furcal lamella, medial view (right lamella with 8 claws). C, left lateral (compound) eye, lateral view (dorsal above).