Paratya gariwerdensis, Suter & Mynott & Crump, 2022

Suter, Phillip J., Mynott, Julia H. & Crump, Megan, 2022, New species of Paratya (Decapoda: Atyidae) from Australian inland waters - linking morphological characters with molecular lineages, Memoirs of Museum Victoria (Mem. Mus. Vic.) 81, pp. 55-122 : 106-110

Paratya gariwerdensis n. sp.

Figures 30 , 31

http://zoobank.org/urn:lsid:zoobank.org:act:D691687B-83DC-

4E45-81AB-26BE4F224714

Lineage D McClusky (2007)

Type Material: Holotype Victoria. Stokes R near Dartmoor − 37.8745 S, 141.3014 E, 3 February 2018 ( PS). Body in ethanol and antennae, mouthparts, pereiopods and abdominal structures dissected, mounted on 2 slides. Accession Ref. PS41 Genbank Registration OL 420914, Museum of Victoria Ref No NMV J75170 .

Paratypes: Victoria. Stokes R near Dartmoor − 37.8745 S, 141.3014 E, 3 February 2018 Accession Ref PS40 , Genbank Registration OL420913, PS46 Genbank Registration OL420918 ( PS), NMV J75171 – J75172 ; bodies in ethanol and other structures dissected, mounted on 2 slides each; Wannon R S of Coleraine − 37.6652 S, 141.6632 E, 3 February 2018 Accession Ref. PS42–43 Genbank Registration OL420915 ( PS) NMV J75173 – J75174 .

Material Examined: Victoria. Stokes R near Dartmoor − 37.8745 S, 141.3014 E, 3 February 2018 ( PS); Wannon R south of Coleraine − 37.6652 S, 141.6632 E, 3 February 2018 ( PS) .

Diagnosis: Paratya gariwerdensis differs from all other species by the following combination of characters: rostrum long, 4.00– 6.25 mm, extending beyond antennular peduncle and just to end of scaphocerite, rostral length 1.02–1.25 times longer than carapace, dorsal edge curved downwards to tip, narrow and pointed; rostral length 8.40–12.50 times greater than width; dorsally armed with 22–29 teeth, ratio of rostral spines to rostral length is 4.21–6.67; 1–2 postorbital spines; ventrally with 7–10 large serrations over a length of 1.30–2.35 mm, 2–3 spines posterior to greatest depth, distal half of ventral edge straight; ratio of ventral spine length to rostral length is 0.32–0.38 and 2.60–4.00 more dorsal spines than ventral spines; rostral length 1.27–1.35 times length of scaphocerite. Antennular peduncle 2.85–3.63 mm long, not reaching distal tip of scaphocerite, length 0.89–0.94 times length of scaphocerite. Stylocerite 1.35–2.08 mm long, length 6.60–8.30 times width, 0.38–0.43 times carapace length, reaching beyond distal border of peduncle segment but not to end of broad acute process on distal angle of first segment. Right mandible with 4 teeth in a single incisor process with all teeth approximately equal sized; spine row immediately below teeth with 5–8 lifting spines. Scaphognathite of maxilla 2 truncated distally. Pereiopod 1, 3.55–4.10 mm long, 0.82–0.99 times carapace length. Chelae short and broad, 1.10–1.30 mm long, propodus 2.44–3.07 times as long as wide, 1.91–2.19 times longer than dactylus, 1.21–1.33 times longer than carpus; palm length 1.39– 1.67 times longer than wide and 1.08–1.20 times dactylus length. Carpus very short, 2.19–2.50 times as long as greatest width. Pereiopod 2 5.05–5.98 mm long, 1.20–1.40 times carapace length. Chelae long and slender 1.15–1.30 mm long, approximately two-thirds length of carpus, 2.61–3.47 times as long as wide, palm length 1.22–1.73 times longer than width and 0.84–0.96 times dactylus length. Propodus 1.68–2.04 times longer than dactylus. Carpus 6.27–7.82 times as long as greatest width. Pereiopod 3 dactylus with prominent terminal claw and 6–7 strong spines on medial margin; propodus length 3.27–3.84 times longer than dactylus, length 10.29–13.00 times longer than wide with 11–13 spines on inner margin. Pereiopod 4, 5.40–7.00 mm long, 1.32–1.54 times carapace length: dactylus with prominent terminal claw and 7–8 spines on medial margin; propodus length 3.75–3.90 times longer than dactylus, length 11.43–14.29 times longer than wide, with 10– 11 spines on medial margin. Pereiopod 5, 5.65–7.80 mm long, 1.38–1.57 times longer than carapace; dactylus with prominent terminal claw and very regular, comb–like row of 44–54 small spines on medial margin; propodus length 3.00–3.11 times longer than dactylus, length 11.63–17.40 times longer than wide with 8–13 long medial teeth and no spines on external margin. Posterior margin of telson convex with 1 pair of teeth-like spines outermost, 8–9 long strong terminal setose spines.

Carapace length 4.00 (3.60–4.10) mm.

Rostrum long, 4.40 (4.00–6.25) mm, extending beyond antennular peduncle and just to end of scaphocerite (fig. 30a), rostral length 1.10 (1.02–1.25) times longer than carapace, dorsal edge curved downwards to tip, narrow and pointed; rostral length 9.78 (8.40–12.50) times greater than width; dorsally armed with 28 (22–29) teeth, ratio of rostral spines to rostral length is 6.36 (4.21–6.67); 2 (1–2) postorbital spines (fig. 30a); ventrally with 7 (7–10) large serrations over a length of 1.50 (1.30–2.35) mm, 2–3 spines posterior to greatest depth (fig. 30a), distal half of ventral edge straight; ratio of ventral spine length to rostral length is 0.33 (0.33–0.38) and 4.00 (2.60–4.00) more dorsal spines than ventral spines; rostral length 1.35 (1.27–1.35) times length of scaphocerite.

Antenna 1 (fig. 30b) peduncle 3.05 (2.85–3.63) mm long, not reaching distal tip of scaphocerite, length 0.94 (0.89–0.94) times length of scaphocerite. Stylocerite 1.70 (1.35–2.08) mm long, length 7.56 (6.60–8.30) times width, 0.43 (0.38–0.43) times carapace length, reaching beyond distal border of peduncle segment but not to end of broad acute process on distal angle of first segment (fig. 30b).

Antenna 2 (fig. 30c) second segment of peduncle 0.93 (0.88–1.13) mm long, 0.28 (0.28-0.31) length of scaphocerite and 2.31 (2.31–3.66) longer than wide. Scaphocerite 3.25 (3.15–3.90) mm long, 2.95 (2.95–3.56) longer than wide, 0.81 (0.78–0.88) times length of carapace.

Mouthparts. Left mandible (fig. 30d, e) with 4 teeth separated by a ridged notch from 1 less distinct apical tooth; spine row immediately below incisor process of 5–7 rugose spines (lifting spines); spine row above molar process of approximatelyover 20 sparsely setose spines. Right mandible (fig. 30f, g) with 4 teeth in a single incisor process with all teeth approximately equal sized; spine row immediately below teeth with 5–8 lifting spines; spine row above molar process. Molar process ridged.

Maxilla 1 (fig. 30h) as for P. australiensis .

Maxilla 2 scaphognathite truncated distally, not extending to apex of upper endite (fig. 30i); palps small, terminal parts narrow and with 1 sub–apical setose spine.

Maxilliped 1 (fig. 30j) as for P. australiensis .

Maxilliped 2 (fig. 30k) endopod 0.75 (0.73–0.93) mm long; basal segment length short, exopod long and narrow 1.75 (1.19–1.75) mm long, exopod 2.34 (1.28–2.34) times longer than endopod. Epipodite with podobranch.

Maxilliped 3 (fig. 31i) endopod 4.63 (4.20–5.88) mm long, 2.37 (2.37–2.92) times longer than exopod; with 3 distal segments of similar length; basal segment curved, apical segment with large terminal claw, medial distal margin with 9 (6–9) broad teeth-like spines, largest 1 or 2 in basal third, outer margin with 2 (2–4) teeth-like spines plus 1 apical spine. Exopod long and narrow, 1.95 (1.55–2.25) mm long, tip reaching basal third of mid segment.

Thoracic appendages. Pereiopod 1 (fig. 30m) 3.60 (3.55– 4.10) mm long, 0.90 (0.82–0.99) times carapace length. Chelae short and broad (fig. 31b), 1.10 (1.10–1.30) mm long, propodus 2.44 (2.44–3.07) times as long as wide, 1.91 (1.91–2.19) times longer than dactylus; palm length 1.39 (1.39–1.67) times longer than wide and 1.09 (1.08–1.20) times dactylus length. Carpus very short, 2.19 (2.19–2.50) times longer than greatest width, broadening distally, distal margin excavate. Segment ratios 0.66 (0.60–0.66): 1.26 (1.21–1.33): 1.00 (0.88 [0.88–1.08] mm): 1.23 (1.16–1.33): 0.63 (0.42–0.63): 2.49 (1.58–2.49). Exopod extending to mid carpus (apex merus–mid carpus).

Pereiopod 2 (fig. 30n) 5.08 (5.05–5.98) mm long, 1.27 (1.20– 1.40) times carapace length. Chelae long and slender (fig. 31c) 1.18 (1.15–1.30) mm long, 2.61 (2.61–3.47) times longer than wide, palm length 2.00 (1.22–1.73) times longer than width, 0.96 (0.84–0.96) times dactylus length. Propodus length 2.61 (2.61– 3.29) times width, 2.04 (1.68–2.04) times longer than dactylus. Carpus 6.27 (6.27–7.82) times longer than greatest width, slightly broader distally, distal margin with small excavation. Segment ratios 0.33 (0.33–0.37): 0.68 (0.60–0.68): 1.00 (1.73 [1.73–2.15] mm): 0.81 (0.74–0.81): 0.45 (0.43–0.45): 1.22 (1.11–1.22). Exopod extending to apex of merus.

Pereiopod 3 (fig. 31a, b) slightly longer than pereiopod 2 and more slender 5.83 (5.53–7.13) mm long, 1.46 (1.35–1.61) times carapace length. Dactylus with prominent terminal claw and 7 (6–7) strong spines on medial margin (fig. 31e). Propodus length 3.27 (3.27–3.84) times longer than dactylus, length 10.29 (10.29–13.00) times longer than wide with 12 (11–13) spines on inner margin. Merus with 1 strong spine on medial margin and 1 near ventral distal margin. Segment ratios 0.48 (0.48–0.53): 1.57 (1.57–1.95): 1.00 (1.15 [1.00– 1.25] mm): 1.96 (1.96–2.15): 0.54 (0.54–0.75): 1.52 (1.50– 1.92). Exopod extends to mid merus.

Pereiopod 4 (fig. 31c d) similar to pereiopod 3, 5.68 (5.40–7.00) mm long, 1.42 (1.32–1.54) times carapace length. Dactylus with prominent terminal claw and 8 (7–8) spines on medial margin (fig. 31g). Propodus length 3.81 (3.75–3.90) times longer than dactylus, length 11.43 (11.43–14.29) times longer than wide, with 11 (10–11) spines on medial margin; merus with 1 strong spine on medial margin and 1 near ventral distal margin. Segment ratios 0.53 (0.50–0.53): 2.00 (1.88–2.00): 1.00 (1.00–1.25) mm: 2.05 (1.95–2.05): 0.63 (0.58–0.63): 1.80 (1.60–1.80). Exopod extends to mid third of merus.

Pereiopod 5 (fig. 31e f) slightly longer than pereiopods 4, 5.78 (5.65–7.80) mm long, 1.44 (1.38–1.57) times longer than carapace. Dactylus with prominent terminal claw and very regular, comb–like row of 44 (44–54) small spines on medial margin (fig. 31i). Propodus length 3.00 (3.00–3.11) times longer than dactylus, length 11.63 (11.63–17.40) times longer than wide with 11 (8–13) long medial teeth and no spines on external margin. Carpus with 1 large spine near distal margin. Merus with 1 strong medial spine and 1 distal spine Segment ratios 0.84 (0.67–0.84): 2.51 (2.10–2.51): 1.00 (0.93 [0.93–1.30] mm): 2.00 (1.77–2.00): 0.73 (0.65–0.88): 1.68 (1.35–1.68). Exopod extends to basal third to mid third of merus.

Abdomen. Pleopods peduncle of first pleopod short 0.28 (0.28–0.35) times length of carapace length, 2.20 (2.20–3.36) times width, exopod 1.52 (1.27–1.52) times peduncle length, endopod 0.64 (0.64–0.80) times peduncle length. (fig. 31l); second pleopod peduncle short, 0.34 (0.34–0.40) times length of carapace, 2.62 (2.62–4.13) times width, exopod 1.27 (1.21–1.36) times peduncle length, endopod slightly shorter 1.16 (1.08–1.32) times peduncle length. Length of first peduncle 1.25 (1.00–1.33) times length of second peduncle.

Telson (fig. 31g h) length 2.80 (2.63–2.80) mm, 0.70 (0.53– 0.70) times carapace length, 3.03 (2.76–3.06) times as long as greatest width, and tapering distally. Dorsal surface with 2 pairs of strong submarginal teeth-like spines. Posterior margin convex with 1 pair of teeth-like spines outermost, 9 (6–9) long strong terminal setose spines (fig. 31h).

Uropods slightly longer than telson.

Males smaller than females, carapace length 4.34 mm; endopod of first pleopod strongly excavated apically with 8–10 external spines and 19 long setae on inner margin (fig. 31j).

Etymology: Gariwerd is the aboriginal name for the Grampians Mountains, the Grampians (Gariwerd) National Park in south-western Victoria.

Comments: Paratya gariwerdensis is restricted to the south-western Victoria in streams that drain the Grampians Mountains where it has been recorded with P. arrostra and P. tasmaniensis .

The long concave rostrum extending beyond the antennular peduncle is a character shared with P. walkeri , P. spinosa , P. arrostra , P. williamsi and P. tasmaniensis . Three of these species ( P. walkeri , P. spinosa and P. williamsi ) have not been recorded in Victoria.

Paratya gariwerdensis can be distinguished from the species with a long rostrum by a combination of characters in Table 2 including: ventral spines cover length of 1.30–2.35 mm; stylocerite extending to mid process on apex of basal segment of antennule 1; carapace length of 3.60–4.10 mm; dactylus 3 with 6–7 medial spines; dactylus 4 with 7–8 medial spines; pereiopod 1 length 0.82–0.99 times carapace length; pereiopod 4 propodus length 1.88–2.00 times longer than carpus 4 length; dactylus 5 length 0.67–0.84 times longer than carpus 5 length; propodus 5 length 2.10–2.51 times longer than carpus 5 length; pereiopod 1 length 3.55–4.10 mm; pereiopod 2 length 5.05–5.98 mm; pereiopod 3–5 less than 7.80 mm; scaphognathite of maxilla 2 truncated; right mandible with a single group of incisor teeth, all 4 of similar size

Figures

Figure 30. Paratya gariwerdensis n.sp.: a) head region and rostrum; b, antenna 1 peduncle and stylocerite; c, scaphocerite; d, left mandible; e, enlarged incisors; f, right mandible; g, enlarged incisors; h maxilla 1; i, maxilla 2; j, maxilliped 1; k maxilliped 2; l, maxilliped 3; m, peraeopod 1; n, peraeopod 2. Scale lines 0.2mm.

Figure 31. Paratya gariwerdensis sp. nov.: a, pereiopod 3; b, dactylus 3; c, pereiopod 4; d, dactylus 4; e, pereiopod 5; f, dactylus 5; g, telson; h, telson terminal spines; i, pleopod 1 of female; j, endopod of pleopod 1 of male. Scale lines 0.2 mm.