Paralimnadia ammolophos, Timms, Brian V., 2016

Timms, Brian V., 2016, A review of the Australian endemic clam shrimp, Paralimnadia Sars 1896 (Crustacea: Branchiopoda: Spinicaudata), Zootaxa 4161 (4), pp. 451-508 : 503-505

Key to species of Paralimnadia based on egg morphology

This key is based on scanning electron micrographs of eggs removed from adults identified to genus. Eggs can also be viewed dried under a light microscope with incident light. Owing to the amount of character overlap with eggs of species of Eulimnadia , caution must be used if this key is used on field collected eggs in the absence of adults.

1. Eggs subspherical, with or without ridges, projections or knobs................................................. 2

- Eggs cylindrical, or cylindrical with one end projecting, or with a broad medial crest............................... 14

2. Eggs with polygonal patterns present or not; pronounced knobs or projections present............................... 3

- Eggs ridges and polygonal patterns present; pronounced knobs or projections lacking................................ 7

3. Eggs with acute, subacute, or rounded projections OR lamellar flanges........................................... 4

- Eggs with rounded, subspherical knobs, OR 6 or 7 large, well spaced, wedge shaped flanges......... P. ammolophos n. sp.

4. Projections separated by elongated polygons, or ridges/grooves..................................................

- Projections crowded, no polygons between projections, or if depressions are present, then each depression not bearing a single groove............................................................................... P. hyposalina n. sp.

5. Projections on ridges delimiting elongated polygons, bearing one central groove.................................... 6

- Projections separated by ridges/grooves that extend from the egg lower surface, up each projection nearly to apex… P. s o rd i d a

6. Grooves wide and infilled; polygons approximately 14 or fewer per side; projections typically narrow, spiniform, with length generally longer than width at midlength............................................................. P. badia

- Grooves tightly closed; polygons approximately 16 or more per side; projections typically lamellar, cariniform, with length generally subequal to width at midlength.......................................................... P. cygnorum

7. Polygons each bearing a central groove or floor, with groove or floor width at least 0.25 times groove or floor length...... 8

- Polygons each bearing a single central groove, with groove width 0.16 times or less groove length..................... 9

8. Polygon ridges rounded in cross section.................................................... P. multispinosa n. sp.

- Polygon ridges triangular in cross section...................... P. urukhai group (pro partim), P. stanleyana (pro partim)

9. Polygon walls crested, triangular in cross section, with long slope from ridge crest to groove........................ 10

- Polygon walls smooth, rounded in cross section, with abrupt transition to groove................................. 13

10. Polygons not arranged in three discreet rows, some rows forming, but never complete..............................11

- Polygons arranged in three discreet rows, with polar polygons variable....................... P. stanleyana (pro partim)

11. Eggs ~100 µm in diameter............................................................................. 12

- Eggs ~ 150 µm in diameter............................................................. P. westraliensis n. sp.

12. Polygons (edges determined at ridge crests) generally rectangular, length generally>2 times width.. P. queenslandicus n. sp.

- Polygons (edges determined at ridge crests) generally oval, length generally <2 times width.......................................................................................... P. saxitalis n. sp., P. urukhai group (pro partim)

13. Eggs ~100 µm in diameter............................................................ P. queenslandicus n. sp.

- Eggs ~ 150 µm in diameter............................................................. P. westraliensis n. sp.

14. Eggs with broad crests................................................................................. 15

- Eggs with one end projecting, crests lacking..................................................... P. flavia n. sp.

15. Crests only on cylinder margins.............................................................. P. monaro n. sp.

- Crests on cylinder margins and transversely across cylinder middle................................. P. montana n. sp.

Key to male Paralimnadia (See Fig. 24 )

1. Cercopod completely inerm; 20 trunk segments........................................................ P. badia

- Cercopod with basal setae or spines; 15–18 trunk segments*................................................... 2 *Occasional P. bishopi specimens may have 19 or 20 trunk segments, but they always have cercopod setae

2. Cercopod with a row of basal spines, usually ca 7–11........................ P. urukhai (pro partim), P. montana n. sp.

- Cercopod with a row of basal setae, number 6–24............................................................ 3

3. Cercopod with an inerm section between the basal setae and seta midlength; usually> 22 telsonic spines [Some P. q u e e n - slandicus have>22 telsonic spines but they have long cercopod setae (> 3 × cercopod basal diameter) whereas other species in this couplet have short cercopod setae; besides they lack an inerm section along the cercopod]......................... 4

- Cercopod with a complete row of setae between base and spine midlength; rarely>20 telsonic spines................... 5

4. Long palp of 1st clasper with 2 palpomeres. Male rostrum triangular and at 110° to frons............ P. multispinosa n. sp.

- Long plap of 1st clasper with 3 palpomeres. Male rostrum broad, with a rounded apex and at 90° to frons.................................................................................................... P. westraliensis n. sp.

5. All or most cercopod setae long (>3× cercopod basal diameter)................................................. 6

- Cercopod setae short or of medium length (<1–2 × basal cercopod diameter)....................................... 9

6.>15 long cercopod setae; cercopod basal division>65% of whole............................................... 7

– <13 long cercopod setae; cercopod basal division <55% of whole............................................... 8

7. Setae vary from long to short along cercopod; 16 or 17 trunk segments; no spines at palpomere 1–2 junction................................................................................................ P. queenslandicus n. sp.

- Longest setae from 3rd to 10th along cercopod; 18 trunk segments; ~ 3 spines at palpomere 1–2 junction of 2nd clasper................................................................................................. P. flavia n. sp.

8. Cercopod setae all of same length; 3 short spines at palpomere 1–2 junction....................... P. ammolophos n. sp.

- Cercopod setae variable in length, first and last shortest; 5 spines, some long at palpomere 1–2 junction..... P. bishopi n. sp.

9. Cercopod setae short (ca subequal or less to basal cercopod diameter)........................................... 10

- Cercopod setae of moderate length (2× basal cercopod diameter)............................................... 12

10. Trunk segments 15 or 16; antennomeres 7–10. Spines on 2nd clasper palp, 3 at palpomere 1–2 junction, 2 laterally on 1st pal- pomere............................................................................ P. urukhai (pro partim)

- Trunk segments>17; antennomeres usually>11; no spines on 2nd clasper plap..................................... 11

11. Cercopod very short setae (most <1 × cercopod basal diameter); clasper with large (subequal to basal diameter terminal knob) sharp projection on mediodistal corner of hand.................................................... P. stanleyana

- Cercopod with short setae (1 to 1.25 × cercopod basal diameter); clasper with moderate length (<0.5 basal diameter of terminal knob) blunt projection on mediodistal corner of hand............................................. P. monaro n. sp.

12. Clasper palpomeres with no spines at 1–2 junctions; projection on mediodistal corner of hand triangular, length ~ 0.25 basal

diameter of knob............................................................................. P. cygnorum - Clasper palpomeres with 1–5 spines at 1–2 junctions; projection on mediodistal corner of hand a rounded timidity........ 1 3

13. Clasper with long palps of 2 palpomeres only; palpomere 1–2 junctions with 1–3 spines................ P. saxitalis n. sp.

- Clasper with long palps of 3 palpomeres; palpomere 1–2 junctions with 4 or 5 spines............................... 14

14. About 14 telsonic spines; last cercopod seta same length as others. Male rostrum at 90° angle to frons... P. hyposalina n. sp.

- About 18–22 telsonic spines; last cercopod seta shorter than others. Male rostrum at 110° angle to frons.......... P. sordida

Figures

FIGURE 24. Terms used in descriptions of Paralimnadia in particular and of limnadiids in general. Note that for the clapser, the endite component of each part is added in brackets. Also note that the posterior spine row is double and is often erroneously called the dorsal spines.