Cherax woworae, Patoka & Akmal & Bláha & Kouba, 2023

Patoka, Jiří, Akmal, Surya Gentha, Bláha, Martin & Kouba, Antonín, 2023, Cherax woworae, a new freshwater crayfish (Decapoda: Parastacidae) from Southwest Papua Province, Indonesia, Zootaxa 5325 (4), pp. 582-592 : 584-589

Cherax woworae n. sp.

( Figs. 1–2 )

Type material. All from Teminabuan District, South Sorong Regency, Southwest Papua Province, Indonesia; collected by anonymous Indonesian supplier. Holotype: MZB Cru 5644 , ♁. Allotype: MZB Cru 5645 , ♀. Paratypes: MZB Cru 5646 , ♁, MZB Cru 5647 , ♁, MZB Cru 5648 , ♁.

Diagnosis. Carapace surface smooth except for 3 or 4 small, spiniform tubercles on branchial surface posterior to cervical groove. Eyes large, pigmented, cornea slightly broader than stalk. Rostrum lanceolate with excavated margins, non-setose; margins with 2 or 3 prominent teeth; acumen straight, rostral carinae prominent. Postorbital ridges prominent, with acute tubercle at anterior terminus. Indistinct bulge at rostral base. Scaphocerite evenly tapering to apex, with single distinct distal spine. Antennular peduncle reaching slightly beyond acumen; antennal peduncle reaching slightly behind scaphocerite apex. First cheliped with uncalcified patch on lateral margin of chelae of adult male, pale, translucent, extending from about the middle of palm to about one-fifth of pollex (fixed finger); pollex cutting edge with row of small granules on proximal half and single large tubercle at midlength; articulations steel blue with pale joints in life; fingers whitish or yellowish basally, black distally with small hooked orange tips; row of blunt spines on inner lateral margin of palm, deep blue. Walking legs deep blue with pale articulations.

Description of holotype male ( Figs. 1a, b , 2a–g ). Body and eyes pigmented. Carapace subovate, slightly compressed laterally, 1.1 times wider than pleon.

Rostrum ( Fig. 2b ) relatively slender, lanceolate, 2.5 times as long as wide, reaching slightly beyond end of second article of antennular peduncle; acumen straight, not deflected or upturned; indistinct bulge at proximal part of rostrum. Margins elevated, anteriorly convergent throughout length to acumen, posteriorly forming prominent carinae, extending as slight elevation posteriorly onto carapace, gradually fading and indistinct behind middle of PCL; lateral margin bearing 3 slightly upturned prominent teeth on distal half; upper surface smooth, non-setose, median carina absent.

Postorbital ridges ( Fig. 2a, b ) prominent, strongly elevated posteriorly, gradually fading, indistinct in remaining half of PCL. Anterior terminus of postorbital ridges with slightly upturned spiniform tubercle. Areola 1.5 times as long as broad at narrowest part ( Fig. 2b ). Length of areola 31% of CL; surface smooth and pitted. Cervical groove distinct, non-setose. Carapace surface smooth, pitted, with group of 4 anteriorly directed small spiniform tubercles lateral and posterior to cervical groove at level of antennae and below.

Eyes ( Fig. 2a, b ) well-developed, relatively large; cornea globular, darkly pigmented, about as long as eyestalk and slightly broader.

Antennule and antenna normal in shape. Antennular peduncle reaching slightly behind rostral acumen.

Antennae shorter than body; peduncle reaching slightly behind apex of scaphocerite. Coxopodite with spiniform tubercle anteriorly; basipodite with lateral and ventral spiniform and hooked tubercles. Scaphocerite ( Fig. 2e ) horizontal; lamina 2.5 times as long as broad, broadest at midlength, convex in distal part becoming narrower at base, reaching slightly beyond antennular peduncle; regularly tapering to apex; thickened outer lateral margin with prominent spiniform tubercle at apex reaching distinctly beyond the lamina; rounded inner margin densely setose.

Epistome ( Fig. 2f ) with subcordiform median lobe tapering to tip and constricted at base, margins setose. Lateral parts of epistome with two groups of 4–7 small granules separated by smooth area; central part smooth with fovea, not pitted; epistomal zygoma prominent and thick, moderately arched with oblique arms.

Maxillipeds 3 reaching end of antenular peduncle.

Male first chelipeds ( Fig. 2c, d, g ) equal in form and size. Chelae 2.1 times as long as broad and 5 times as long as height, compressed; chela surface smooth, pitted; palm 1.5 times longer than fingers; chelae 0.8 times shorter than carapace length; fingers slightly gaping in distal half; dactyl (movable finger) broad at base, tapering slightly towards tip; pollex (fixed finger) triangular and slightly curved in distal half, merging gradually into palm; propodus 1.7 times broader than dactyl at base. Outer lateral margin of chelae with swollen soft, uncalcified patch extending from near middle of palm to about one-fifth of pollex ( Fig. 2g ); entire inner lateral margin of palm covered with slender row of 10 bluntly topped teeth. Dactyl cutting edge with small granular teeth along entire length, with large prominent tooth near middle of cutting edge; non-setose. Dactyl tip with acute, hooked spine pointing outwards at angle of approximately 45°. Pollex cutting edge with row of small granules on proximal half and single large tubercle at midlength; setose in posterior part of ventral surface. Pollex tip with acute, moderately hooked spine. Propodal and dactyl tips slightly crossing when fingers closed. Carpus smooth, pitted; with well-developed acute and hooked spiniform tubercle in middle of dorsolateral inner margin (as characteristic for Cherax ), terminating in straight spiniform tubercle. Inner carpal surface covered with tiny setae; fovea indistinct and not pitted, inner margin with acute straight, spiniform tubercle and 2 indistinct granules; outer margin with straight, spiniform tubercle. Merus laterally strongly depressed basally; surface smooth and pitted; anteriorly directed dorsal spine; row of 3 anteriorly directed spines on ventral surface; row of small granules on entire inner ventrolateral margin; chela 1.8 times longer than merus.

Pereiopod 2 reaching slightly behind apex of scaphocerite. Palm as long as fingers; fingers and palm sparsely setose; tips of fingers hooked. Carpus 1.4 times longer than palm. Merus 1.7 times longer than carpus and 2.0 times longer than ischium.

Pereiopods 3 lost in holotype, in paratype 1 (MZB Cru 5646), 1.3 times longer than second pereiopod. Palm 1.4 times longer than fingers. Fingers sparsely setose; tips of fingers hooked. Carpus 1.4 times longer than palm. Merus 1.4 times longer than carpus and 2.3 times longer than ischium.

Pereiopod 4 reaching proximal one-third of scaphocerite. Propodus densely setose. Dactyl slightly hooked. Propodus 1.3 times longer than carpus. Merus 1.7 times longer than carpus and 2.0 times longer than ischium.

Pereiopod 5 reaching slightly behind anterior terminus of postorbital ridge. Propodus setose. Dactyl straight. Propodus 1.7 times longer than carpus. Merus 1.8 times longer than carpus and 1.8 times longer than ischium.

Pleon dorsal surface smooth medially; pleura smooth and pitted. Each somite densely setose with short setae on ventral posterior margin.

Telson with 2 posteriorly directed spiniform tubercles in caudolateral corners.

Uropodal protopod with posteriorly directed spiniform tubercle on distal margin. Endopod with 2 posteriorly directed spiniform tubercles in middle and outer margin of mesial lobe. Exopod with transverse row of posteriorly directed diminutive spiniform tubercles ending in 2 larger, posteriorly directed spiniform tubercles on outer margin of mesial lobe.

Allotype female. Differing from holotype as follows: rostrum slightly curved; soft uncalcified patch on palm absent ( Fig. 2h ); first chelae 2.5 times as long as broad, 6.3 times as long as height, palm 1.3 times longer than fingers, tubercles on pollex cutting edges smaller and less prominent than in holotype; pleon as broad as carapace; cervical groove with group of 4 (right side) and 3 (left side) anteriorly directed prominent tubercles.

Sternal keel ( Fig. 2i ): Thoracic sternum from sternite X–XII with wide and sloped median keel anterior margin to base of coxa of pereiopod 1 to base of coxa of pereiopod 3. Sternite XII with rounded narrow and small lateral processes. Small median keel at coxopodite of pereiopod 4. Sternite XIII with parallel and wide lateral processes, angle of lateral margin with large scoops.

Paratypes. All paratypes are adult males. The morphological characteristics are in detail given in Table 2 .

Remarks. The new species, Cherax woworae n. sp., is genetically and morphologically most similar to Cherax gherardii . Both species may be easily distinguished using sequence divergence or by colouration; rostrum length; chelae shape; antennae length, and areola width.

The single well-developed acute and hooked spiniform tubercle in the middle of dorsolateral inner margin of the carpus is characteristic of the genus Cherax . Both holotype and allotype chelae were without visible damage. The left pereiopod 3–4, right pereiopod 3 and left antenna are lost in the holotype, whereas a new tiny regenerated limb is obvious in the position of the right pereiopod 3. The holotype has prominent erosion on the carpus of the right cheliped. The allotype (female) is damaged within the morphological analysis (pleon separated from cephalothorax, chelipeds, pereiopods and left scaphocerite separated).

Size. Holotype (male, MZB Cru 5644): CL = 39 mm, CW = 17 mm, PCL = 29 mm. Allotype (female, MZB Cru 5645) CL = 42 mm, CW = 18 mm, PCL = 31 mm. Paratype 1, (male, MZB Cru 5646): CL = 39 mm, CW = 16 mm, PCL = 29 mm. Paratype 2 (male, MZB Cru 5647): CL = 48 mm, CW = 20 mm, PCL = 35 mm. Paratype 3 (male, MZB Cru 5648): CL = 44 mm, CW = 19 mm, PCL = 33 mm. Other morphological measurements of the holotype, allotype and paratypes are given in Table 2 .

Colouration in life. Background colour steel blue, marbled on carapace sides with numerous tiny pale spots. Soft distal part of caudal tail fan orange. Chelipeds steel blue with pale joints. Palm of chelae steel blue. Fingers whitish or yellowish in basal part, black in distal part with hooked small orange tips. Ventral surface of palm pale (yellowish or whitish) in outer half and steel blue in inner half; fingers pale in basal half (dactyl) or base (pollex) and black distally. Row of blunt spines on inner lateral margin of cheliped palm deep blue. Other pereiopods and maxillipeds deep blue with pale joints. Both antennal and antennular peduncle steel blue, flagella brown, setae orange. Uncalcified patch on outer lateral margin of male palm pale and whitish. Ventral surface of cephalothorax and pleon pale.

Systematic position. Cherax woworae n. sp. is morphologically most similar to C. gherardii and differs from this species in the following characters: rostrum 3.6 times as long as wide in C. gherardii versus 2.0– 2.5 in C. woworae ; first chela are 2.6–3.4 times as long as broad and 7.1–8.7 times as long as height in C. gherardii versus 2.1–2.5 times as long as broad and 4.5–6.3 times as long as height in C. woworae ; antennae similarly long as body in C. gherardii but shorter in C. woworae ; areola 1.8 times as long as broad at the narrowest part in C. gherardii versus 1.5 times as long as broad at the narrowest part in C. woworae .

Etymology. The specific name, the singular genitive of Wowor, honours Dr. Daisy Wowor, the systematic carcinologist and curator of the crustacean collection at the Museum Zoologicum Bogoriense, Java, Indonesia, who is among others interested in the taxonomy of New Guinean Cherax crayfish.

Common name. Since “Blue Moon” is used as a trade name for various species of Cherax crayfish, it cannot be accepted as a common name. Therefore, we proposed a Steel Blue Crayfish, as a common name for the new species, Cherax woworae n. sp.

Distribution. Based on information from the supplier, C. woworae n. sp. occurs in freshwater bodies in Teminabuan, South Sorong Regency, Bird’s Head Peninsula, Southwest Papua Province, Indonesia ( Fig. 3 ). To improve the knowledge of the distribution of the species, future field surveys are recommended. Based on previous studies and available sequences, C. woworae n. sp., together with C. wagenknechtae , were found for first time outside of their native ranges in thermal waters in Hëjo Brook and Városliget, Hungary (Weipert et al. 2020; Bláha et al. 2022). These individuals were probably released by irresponsible hobbyists and originate from the pet trade.

Phylogenetics. The phylogenetic relationships inferred from two mitochondrial gene fragments (COI and 16S) resulted in a phylogram with a clearly defined species, C. woworae n. sp. ( Fig. 4 ). The new species forms a strongly supported clade as sister to C. gherardii with model corrected differences at 5.6 and 1.2% for COI and 16S genes, respectively. These two species form a sister clade to C. boesemani , from C. woworae n. sp. differ at 13.8 and 4.4% for COI and 16S genes, respectively. From five analyzed specimens, two haplotypes were identified for both genes analysed. Both the moderate level of sequence divergence, along with the morphological differences described above, suggests that C. woworae n. sp. is distinct from the closely related C. gherardii and supports the view that it can be described as a separate species. Phylogenetic analyses showed the assignment of previously studied individuals from Hungarian thermal waters (Weipert et al. 2020; Bláha et al. 2022) to recently described species C. wagenknechtae (GenBank accession numbers MT833298, OT806575 for COI and MT833284, OL828271 for 16S) and C. woworae n. sp. (OL790140 for COI and OL780441 for 16S). These previously analysed individuals shared the same haplotypes with the type sequences of both recently described species ( Table 1 ).

Figures

FIGURE 1. Cherax woworae n. sp., holotype ♁, PCL 29 mm, MZB Cru 5644: a, colour in life; b, colour in preservative.

FIGURE 2. Cherax woworae n. sp., a–g, holotype ♁, PCL 29 mm, MZB Cru 5644; h–i, allotype ♀, PCL 31 mm, MZB Cru 5645: a, lateral view of carapace; b, dorsal view of carapace; c, dorsal view of left chela; d, ventral view of left chela; e, dorsal view of left scaphocerite; f, epistome and coxopodite of antennal peduncles; g, outer lateral margin of right male chela; h, outer lateral margin of right female chela; i, sternal keel. Scale bars = 1 cm.

FIGURE 3. The Bird’s Head Peninsula, Indonesia, and the locality of Cherax woworae n. sp. in Southwest Papua Province indicated by the red dot.

FIGURE 4. Bayesian analysis consensus phylogram of selected Cherax based on combined COI and 16S dataset. Posterior probabilities and ML bootstrap values are displayed next to each node. An asterisk indicates nodes with full support (1/100) in both analyses. The scale bar indicates the substitution rate.