Cherax mosessalossa, Lukhaup & Eprilurahman & Rintelen, 2018

Lukhaup, Christian, Eprilurahman, Rury & Rintelen, Thomas von, 2018, Two new species of crayfish of the genus Cherax from Indonesian New Guinea (Crustacea, Decapoda, Parastacidae), ZooKeys 769, pp. 89-116 : 91-97

Cherax mosessalossa sp. n. Figs 1 , 2 , 3 , 4 , 5

Material examined.

Holotype: male (MZB Cru 4675), under rocks and among roots along banks of Klademak Creek , Sorong City, 0°52'23.59"S, 131°16'24.40"E, West Papua, Indonesia, coll. Christian Lukhaup, Marten Luter Salossa and Salvatore a`Paulo Narahawarin, January 26, 2016 . Allotype: female (MZB Cru 4676), same data as holotype. Paratypes: (MZB Cru 4677), same data as holotype.

Diagnosis.

Carapace surface smooth with scattered fine hairs, five small spiniform tubercles posterior to cervical groove on lateral carapace. Eyes large, pigmented. Cornea slightly broader than eyestalk. Rostrum triangular in shape with elevated margins, setose in the anterior half. Rostral margins with three prominent teeth. Rostral carinae prominent. Postorbital ridges prominent with one acute tubercle at anterior terminus. Uncalcified patch on lateral margin of chelae of adult male white, translucent. Propodal cutting edge with row of small granules and one larger tubercle. Chelipeds blue-grey lateral margins white, posterior lateral part sometimes orange. Fingers dark black blue with hooked yellow tips. Other walking legs blue-gray. Pleon blue-grey with yellow transverse lines.

Description of male holotype

(Figs 2 - 5 ). Body and eyes pigmented. Eyes not reduced. Body subovate, slightly compressed laterally. Pleon narrower then cephalothorax (width 12.9 mm and 13.6 mm, respectively). Rostrum (Figure 3A ) broad in shape, reaching nearly to end of ultimate antennular peduncle more than three times longer than wide (width 3.3 mm at base, length 10,9 mm). Upper surface smooth, short scattered hairs present. Margins slightly elevated continuing in rostral carinae on carapace, almost straight in basal part, distally rather moderately tapering towards apex. Scattered, short, fine hairs present on rostrum surface. Lateral rostral margin bearing three prominent teeth in distal half on right side and two on left, pointing upwards at angle of approximately 45°. Few short hairs present on distal half of outer margins. Acumen with anteriorly orientated spine.

Rostral carinae extending as slight elevation posteriorly on carapace terminating at ending of postorbital ridges. Postorbital ridges well developed, terminating in spiniform tubercle anteriorly, fading at two-thirds of occipital carapace length, posteriorly. (Figure 4 ) Dorsal surface of carapace smooth, scattered fine short hairs present after cervical grove. Cervical and branchiocardiac grooves distinct, setose at middle part, three prominent corneous spine and two smaller spines present at middle part behind cervical groove on lateral sides of carapace.

Areola length 9.3 mm, narrowest width 5.1mm. Length of areola 31.8% of total length of carapace (31.17 mm).

Ventrolateral parts smooth with scattered short hairs; anterior margin strongly produced, rounded upper margin directed inward.

Scaphocerite broadest at midlength, convex in distal part becoming narrower in basal part; thickened lateral margin terminating in large corneous spine, almost reaching distal margin of ultimate segment of antennular peduncle. Right scaphocerite 7.7 mm long and 2.7 mm wide. Proximal margins setose. Antennulae and antennae typical for genus. Antennae approx. 10 % longer then body. Antennular peduncle reaching slightly behind acumen, antennal peduncle reaching slightly behind apex of scapho cerite. Antennal protopodite with spine anteriorly; basicerite with one lateral and one ventral spine.

Mouthparts typical for the genus. Epistome with subcordiform cephalic lobe anteriorly bearing lanceolate cephalomedian projection constricted at base. Lateral margins of lobe not thickened; each lateral margin with two groups of 5-6 tubercles separated by a smooth place. Central part smooth, not pitted, excavate. Eyes rather large; cornea globular, darkly pigmented, nearly as long as eyestalk; eyestalk slightly narrower than cornea.

First pereopod equal in form, chela slightly gaping, equal in size, right cheliped (24.6 mm long, 5.2 mm high, 11.2 mm wide). Right chelae (Figure 3B, C ), strongly compressed. Fingers shorter than palm (dactylus 10.4 mm long). Dactylus broad at base (3.5 mm), tapering slightly towards tip. Tip with sharp, corneous, hooked tooth pointing outwards at an angle of 45°. Cutting edge of dactyl with continuous row of rather small granular teeth and one prominent larger tooth at middle of cutting edge. Ventral and dorsal surface of movable finger with scattered punctuation. Fixed finger triangular, merging gradually into palm, ending in sharp, corneous, hooked tooth, standing almost perpendicular to axis of finger. Tips of fingers slightly crossing when fingers clasp. Upper surface of palm practically smooth, slightly pitted, more densely pitted at margins. Fixed finger with approximately same width as dactyl at base (5.0 mm). Dense, short setae present in posterior ventral part of fixed finger. Cutting edge of fixed finger with row of rather small granular teeth at posterior half and one at middle of anterior part. Scattered, short hairs present in posterior ventral half of dactylus.

Dorsal surface of carpus (8.7 mm) smooth and pitted, with slight excavation in middle part and with a well-developed mesial carpal spine. Ventral carpal surface margins slightly elevated, setose at inner margin and with fovea; inner margin with well-developed ventral carpal spine and ventromesial carpal spine oriented in angle of approx. 45°. Outer lateral margin of chelae with swollen soft and uncalcified patch (7.3 mm) which extends from approx. first third of palm to approx. beginning of the movable finger. Mesial margin of palm slightly elevated, forming slender serrated ridge with row of 10-11 small granular teeth (Figure 5A, B ).

Merus (13 mm) laterally depressed in basal part; surface slightly pitted; small dorsal meral spine present. Inner ventrolateral margin densely covered with small granules, four sharp ventral meral spines present, one at midlength, other in middle of anterior part, third and fourth on distal ventrolateral inner margin.

Ischium (7.8 mm) smooth with two small spines and two granules at midlength of ventrolateral inner margin.

Second pereopod reaching anteriorly to approximately corneus spine of scaphocerite. Finger (3.5 mm) slightly shorter as palm (4.0mm), of same height. Scattered short setae present on dactyl and fixed finger. Cutting edge of fixed finger and carpus with row of dense, short setae. Carpus (5.4 mm), smooth, slightly pitted, longer than palm. Merus (9.5 mm) 1.75 times longer than carpus. Ischium (4.6 mm) approx. as half as long as merus.

Third pereopod overreaching second by length of finger of second pereopods. Fingers shorter than palm.

Fourth pereopod reaching distal margin of scaphocerite. Dactylus with corneous tip. Short scattered setae present. Propodus more than twice as long as dactylus, nearly 1.5 times as long as carpus; somewhat flattened, carrying many stiff setae on lower margin. Merus just slightly longer than propodus.

Fifth pereopod similar to fourth, slightly shorter.

Dorsal surface of pleon smooth, with scattered pits; abdominal segments with short setae present on caudal margins.

Telson with posterolateral spines, dense short setae present in posterior third. Posterior margins setose. Uropodal protopod with two distal spines on mesial lobe. Exopod of uropod with transverse row of posteriorly directed diminutive spines ending in one more prominent spine, posteriorly directed on outer margin of mesial lobe. Terminal half of exopod with small tubercles and short hairs, slightly corrugated. Endopod of uropod smooth. Short scattered hairs present on posterior third of dorsal exopod. Postrolateral spine on outer margin present. Second spine on medial dorsal surface present, directed posteriorly.

Description of allotype female

(Figure 6 ). Chela of first pereopods equal, 2.6 times as long as broad (28.6 mm and 10.9 mm respectively). Mesial margin of palm slightly elevated, forming slender serrated ridge with row of 12-13 small granular teeth. Cutting edge of dactylus with 4-5 rather small granular teeth. Cutting edge of fixed finger with 84-5 small granules. Small scattered short setae visible along ventral cutting edge of chelae, denser and long in ventral posterior area. Tips of fingers slightly crossing when fingers clasp, not gaping. Cervical groove distinct, short setae present at middle part. One prominent corneous spine and two smaller granules present at middle part behind cervical groove on lateral sides of carapace. Pleon just slightly narrower than cephalothorax (widths 12 mm and 12.5 mm respectively). Same colour pattern as in males, less intense.

Size. The largest male examined is the holotype with a carapace length of 31.3 mm, and a total length of 79 mm; the paratype male has a total length of 66.3 mm and the other male has a total length of 59 mm; the allotype female has a carapace length of 40 mm and a total length of 87.7 mm (n = 6).

Colour. The living animals (Figure 1A, B ) are coloured as follows. Male: Chelae dark blue with white margins and white patch. Anterior part usually dark blue. Corneous tooth on tip of fingers orange. Cephalothorax brown-black, with creamy spots laterally. Dark reddish patch on dorsolateral side of the carapace between rostral carinae and cervical grove. Segments of pleon dark blue or brown with yellowish cream transversal band. Lateral pleura slightly lighter with some yellowish cream spots. Walk ing legs dark bluish grey. Distal margin of tail-fan creamy orange to light yellowish. Females: usually same colour as males somewhat less colourful.

Molecular phylogenetic results.

Cherax mosessalossa sp. n. is sister species to Cherax misolicus (16S only, Figure 19 ), both are in turn sister group to C. warsamsonicus . Cherax mosessalossa sp. n. is well isolated from both C. misolicus with a sequence divergence (p-distance, 16S) of 1.8 % and from C. warsamsonicus with a sequence divergence of 2.6 % (16S) and 6.6-7.0 % (COI), respectively, supporting the morphology-based description of C. mosessalossa as a new species.

Systematic remarks.

Among all species of the northern group, C. mosessalossa sp. n. is most similar to C. misolicus , a species that is endemic to Misool Island, one of four major islands in the Raja Ampat Islands in West Papua, Indonesia, and to C. Cherax warsamsonicus , a species that is endemic to the Warsamson River ca. 50 km north of Sorong. Cherax mosessalossa sp. n. differs from C. misolicus and C. warsamsonicus in several characters(see Table 2 ).

Etymology.

Cherax mosessalossa sp. n. is named after the son of our guide Marten Luther Salossa, Moses Yorof Salossa, who died of malaria at the age of 2.

Ecology.

Known only from the Klademak Creek, South Sorong Regency, in the central part of the Kepala Burung (Vogelkop) peninsula. (Figure 8 ) At the sampling site the creek is shallow (20-50 cm) with a moderate flow and had a pH of approximately 6.5. In most parts no water plants are present. The substrate of the creek is gravel or sand and soil mostly covered with silt and detritus, stones and larger rocks (Figure 9 ). Crayfish hide in short borrows in the creek bank, under lager rocks or in detritus that gathers in slower flowing parts of the creek. To improve the knowledge of the ecology and distribution of the species more field surveys will be necessary.

Common name.

As common name for this crayfish we propose Klademak Creek Crayfish.

Figures

Figure 1. Cherax mosessalossa sp. n. A holotype male (MZB Cru 4675) from Klademak Creek, Sorong City B idem, side view.

Figure 2. Cherax mosessalossa sp. n. holotype male (MZB Cru 4675). Scale bar: 10 mm.

Figure 3. Cherax mosessalossa sp. n. holotype male (MZB Cru 4675). A dorsal view of carapace B dorsal view of right chelae C ventral view of right chelae. Scale bars: 10 mm.

Figure 4. Cherax mosessalossa sp. n. holotype male (MZB Cru 4675), dorsal view of cephalothorax. Scale bar: 10 mm.

Figure 5. Cherax mosessalossa sp. n. holotype male (MZB Cru 4675). A right first chela, dorsal aspect B right first chela, ventral aspect. Scale bars: 10 mm.

Figure 6. Cherax mosessalossa sp. n., allotype female (MZB Cru 4676).

Figure 8. The Bird's Head Peninsula, West Papua, Indonesia with the type locality, Klademak Creek, indicated.

Figure 9. Klademak Creek, habitat of the new species.

Figure 19. Phylogenetic relationships of Cherax mosessalossa sp. n. and C. alyciae sp. n. within the northern New Guinea Cherax lineage, reconstructed by BI analyses of two mitochondrial gene fragments. Number on branches show, from top, Bayesian posterior probabilities (> 0.7) and ML / MP bootstrap values (> 50). An asterisk indicates nodes with full support (1 / 100 / 100) in all analyses. The scale bar indicates the substitution rate. See Table 1 for information on the sequenced specimens. A Topology based on concatenated COI and 16 S dataset B Topology based on COI dataset C Topology based on 16 S dataset.