Dardanus longior Asakura, 2006, sp. nov.
Creators: name: Asakura, Akira
Publisher: name: Zenodo
Year: 2006
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Diogenidae
Dardanus
Dardanus longior

description: Dardanus longior sp. nov.
(Figs. 23–29, 32)
Material examined
Holotype: ♂, SL 8.0 mm, Jarvis Island, Phoenix Islands, 2 Oct. 2002, coll. Scott Godwin, JAR­11, AA­05, BPBM­S 12885. Paratypes: 2♂, SL 5.8, 8.5 mm, Jarvis Island, Phoenix Islands, 3 Sept. 2002, coll. Scott Godwin, JAR­07, AA­08, BPBM­S 12884; 1♂, SL 5.7 mm, Jarvis Island, Phoenix Islands, 3 Oct. 2002, coll. Scott Godwin, JAR­9P, AA­ 0 9, BPBM­S 12886; 1Ψ, SL 4.0 mm, Baker Island, Phoenix Islands, 30 Jan. 2002, coll. Scott Godwin, BAK­11P, AA­04, BPBM­S 12878; 1♂, SL 6.3 mm, Baker Island, Phoenix Islands, 23 Jan. 2002, coll. Scott Godwin, BAK­09, AA­06, BPBM­S 12876; 1Ψ, SL 4.3 mm, Baker Island, Phoenix Islands, 24 Jan. 2002, coll. Scott Godwin, BAK­UP, AA­09, BPBM­S 12877; 1♂, SL 9.6 mm, Howland Island, Phoenix Islands, 31 Jan. 2002, coll. Scott Godwin, HOW­SP, AA­02, BPBM­S 12879; 1♂, SL 10.1 mm, Howland Island, Phoenix Islands, 31 Jan. 2002, coll. Scott Godwin, HOW­SP, AA­01, BPBM­S 12880; 1Ψ, SL 3.1 mm, Howland Island, Phoenix Islands, 31 Jan. 2002, coll. Scott Godwin, HOW­SP, AA­03, BPBM­S 12881; 1 ov.Ψ, SL 4.8 mm, 1♂, SL 3.7 mm, Howland Island, Phoenix Islands, 1 Feb. 2002, coll. Scott Godwin, HOW­11P, AA­07, BPBM­S 12882; 1Ψ, SL 3.8 mm, Kingman Reef, Line Islands, 17 Mar. 2002, coll. Scott Godwin, KIN­12, 13, SP, AA­ 10, BPBM­S 12883,
Description
Shield (Fig. 23 A) slightly longer than broad or as long as broad; anterior margin between rostral lobe and lateral projections shallowly concave; lateral margins slightly convex, with rows of long setae. Dorsal surface of shield with scattered tufts of short setae; weakly­calcified Y­shaped linea present posteriorly; gastric pits distinct. Rostral lobe only slightly protruded. Lateral projections bluntly triangular, produced. Posterior carapace lateral elements well calcified, unarmed. Branchiostegites unarmed.
Ocular peduncles (Fig. 23 A) 0.7–0.8 length of shield, subcylindrical, slightly inflated distally and basally; corneas only very slightly dilated. Ocular acicles (Fig. 23 C) broad; distal margins each with 2–4 spines. Interocular plate (Fig. 23 C) with pair of small protrusions.
Antennular peduncles (Fig. 23 A) slender, when fully extended, distal margins of ultimate segments reaching or slightly overreaching bases of corneas; ultimate and penultimate segments unarmed; basal segment with ventromesial distal angle bearing small spine.
Antennal peduncles (Fig. 23 A, B), when fully extended, slightly shorter than or equaling to ocular peduncles not including corneas; fifth to third segments unarmed; second segment with dorsomesial distal angle bearing 1–3 spines, dorsolateral distal angle produced, with 1–2 spines; first segment with ventrolateral distal angle with sharp spine. Antennal acicle (Fig. 23 B) terminating in simple or bifid spine; dorsomesial margin with 2–6 spines; dorsolateral margin with small subdistal spine. Antennal flagella sparsely setose.
Third maxilliped (Fig. 23 D, E) with well­developed crista dentata (Fig. 23 E); basis with or without corneous spine.
Chelipeds vastly unequal, left larger. Left cheliped very stout (Figs. 24, 29 B, C), slightly more elongate in males than in females. Dactyl terminating in large corneous claw; cutting edge with 4–10 variously sized calcareous teeth; upper and outer faces with numerous, truncate corneous tipped spines and numerous, small, truncate corneous spines each accompanied with 1–3 short setae. Fixed finger terminating in large corneous claw; cutting edge with 9–12 calcareous teeth. Palm and fixed finger with outer face bearing numerous, truncate corneous­tipped spines and small, truncate corneous spines each accompanied with generally 1 (ranging 1–3) short seta (Fig. 24 B), lower half of outer face concave; lower margin with row of corneous or corneous­tipped spines and stiff setae; lower portion of inner face with short corneous spines and tufts of stiff setae; upper face of palm with 1 or 2 irregular rows of prominent corneous­tipped spines. Carpus with upper face and upper portion of outer face bearing many prominent corneous­tipped spines and stiff setae, distal margin of outer face armed with small corneous spines and setae, outer face with many small corneous spines and stiff setae. Merus with dorsal and lateral faces bearing stiff setae; ventrolateral distal angle with several large corneous­tipped spines; dorsodistal margin of lateral face with few large corneous­tipped spines. Ischium unarmed.
Right cheliped moderately slender (Figs. 25 A–C, 29D, E), generally setose. Dactyl terminating in large corneous claw; cutting edge with several calcareous teeth; upper face with several strong corneous­tipped spines and scattered small corneous spines; upper and outer faces with stiff setae. Fixed finger terminating in large corneous claw; cutting edge with several small calcareous teeth. Palm and fixed finger with upper, outer and lower faces with tufts of stiff setae; outer face bearing scattered small corneous spines and some larger corneous­tipped spines; upper margin of palm with 1 or 2 irregular rows of prominent corneous­tipped spines; lower face with 1 or 2 irregular rows of corneous spines and stiff setae. Carpus with upper face bearing 4 strong corneous­tipped spines; outer and upper faces with stiff setae. Merus with lateral face bearing 0–2 corneous­tipped spines on ventrodistal angle and few corneous­tipped or calcareous spines on distal margin; outer and upper faces with stiff setae. Ischium unarmed.
Second (Figs. 25 D–H, 29F, G) and right third (Fig. 28 A, B) pereopods generally similar, but second pair more slender than right third; of second pair, left slightly shorter than right. Dactyls of second pair and right third as long as propodi, each terminating in strong corneous claw; dorsal, lateral and mesial surfaces with irregular rows tufts of setae; lateral and mesial faces generally convex and often with shallow longitudinal sulcus on midline of lateral face; ventral margins each with row of 3–5 corneous spines distally. Propodi 1.5–1.7 (second, Fig. 25 F, G) or 1.8–1.9 (right third) length of carpi; dorsal faces flat and broad (second) or comparatively narrower (right third), armed with numerous (second) or comparatively fewer numbers of (right third) corneous spines, dorsodistal margins armed with corneous spines (second) or unarmed (third); lateral faces with few longitudinal rows of tufts of setae. Carpi 0.5–0.6 (second) or 0.6–0.7 (right third) length of meri; dorsodistal angle with corneous­tipped spine. Meri with ventrodistal angle of lateral face bearing spine (second) or unarmed (third), ventrolateral margins with several, small corneous­tipped spines (second) or unarmed (third). Ischia unarmed.
Left third pereopod (Figs. 26, 27, 28 H, I) stout. Dactyl (Fig. 26) as long as propodus, broad, terminating in strong corneous claw; lateral surface (Fig. 26 A, C, D) with dorsal row of strong corneous spines (Fig. 26 C­a), dorsal half with deep longitudinal concavity (Fig. 26 C­b) bearing tiny spines, ventral 0.3–0.5 with numerous strong spines in distal 0.5–0.6 (Fig. 26 C­c) and 1–3 rows of large protuberances armed distally with 1–5 strong truncate spines (Fig. 26 D), most ventral row of these protuberances (Fig. 26 D­d) continuing to large lobes on ventromesial margin; ventral margin (Fig. 26 F) with proximal 0.4–0.5 bearing series of deep furrows producing row of large lobes, ventromesial margin of each lobe armed with 1 or 2 very large, conical corneous spines (Fig. 26 F), distal 0.4–0.6 of ventral margin with few strong corneous spines; mesial face (Fig. 26 B, E) strongly convex, with numerous strong corneous spines on dorsal half and rows of long stiff setae; dorsal margin with row of strong corneous spines and rows of dense long setae. Propodus (Fig. 27) 1.5–1.6 length of carpus, broad; dorsal margin with series of furrows producing row of lobes, lateral face of each lobe armed distally with generally 2–4 (ranging 1–6) flattened, elongate rectangular, corneous spines (Fig. 27 A­a) and dorsomesial surface of each lobe with 1–4 strong spines and stiff setae (Fig. 27 B); lateral face (Fig. 27 A) with dorsal half bearing very deep longitudinal concavity (Fig. 27 A­b) with scattered short spinules, separated by strong narrow medial longitudinal elevation (Fig. 27 A­c) with 1 or 2 irregular rows of protuberances each bearing marginal 1–7 flattened, elongate rectangular corneous spines, from ventral 0.3–0.4 concave (Fig. 27 A­d) with 1 or 2 irregular rows of protuberances each armed with many marginal flattened, elongate rectangular corneous spines; ventral margin with series of deep furrows producing row of large lobes, lateral face of each lobe (Fig. 27 A­e) armed with many marginal flattened, elongate rectangular corneous spines and strong ventrodistal spine, ventromesial margins of ventral lobes (Fig. 27 C) each with 1–4 very large, conical corneous spines and stiff setae; mesial face (Fig. 27 B) strongly convex, with few rows of tufts of very long setae, dorsal margin with row of strong spines and long setae, dorsal half of mesial surface with many strong spines and setae, dorsal half of distal margin armed with corneous spines and fringed with setae. Carpus 0.7–0.8 length of merus. Armament and setation of carpus, merus and ischium similar to those of right third.
Sternite of third pereopods with anterior lobe bearing 1 or 2 rounded projections (Fig. 23 F, G), with long setae anteriorly.
Fourth pereopod (Fig. 28 C) semichelate; dactyl with few short corneous spines on lateral face ventrally; propodal rasp well developed; carpus with 1–3 sharp corneoustipped dorsodistal spines.
Fifth pereopod chelate; rasps of dactyl and propodus well developed.
Male pleon (Fig. 28 D) with second to fifth small left pleopods, fringed with setae; small, elongate fleshy membranous protuberance (Fig. 28 E) with setae present between fourth and fifth pleopods. Female pleon (Fig. 28 F) with second to fifth left pleopods, fringed with setae; second to fourth large, triramous; fifth small, with slender exopod; elongate­triangular fleshy membranous protuberance fringed with setae present between fourth and fifth pleopods.
Uropods markedly asymmetrical, left larger than right; endopods and exopods with well­developed rasps.
Telson (Fig. 23 H, I) with lateral constrictions; marginal area partially calcified; posterior lobes separated by median cleft, left more extended posteriorly than right, with 5–10 spines and long setae on terminal margin.
Color
Color in life unknown. Color in preservative (two years after collection) (Fig. 29): dorsal surface of shield mottled pink or pale orange and white, with dark brown area, midanteriorly. Ocular peduncles pinkish or pale orange. Chelipeds and ambulatory pereopods generally mottled pink or pale orange and white. Tips of fingers of chelipeds and dactyls of ambulatory pereopods whitish; carpi and meri of chelipeds each with bright orange area; carpi of ambulatory pereopods each with dark brown area; articulation of carpi and meri of ambulatory pereopods whitish. Lateral and mesial faces of dactyls of chelipeds and ambulatory pereopods each with small dark brown spot. Bases of tufts of setae on lateral and mesial faces of dactyls and propodi of chelipeds and ambulatory pereopods often dark brown or red. Posterior carapace and pleon pinkish, with mottled white and red.
Etymology
From the Latin longior, the comparative degree of the Latin longus (=long), referring to the comparatively longer propodus of the left third pereopod in this species among the D. sanguinocarpus species complex.
Distribution
Phoenix Islands and Line Islands (Fig. 32).
description: Published as part of Asakura, Akira, 2006, Dardanus sanguinocarpus Degener, 1925 (Crustacea: Decapoda: Anomura: Diogenidae) species complex: a redescription of D. sanguinocarpus and descriptions of three new species, pp. 1-54 in Zootaxa 1230 on pages 37-47, DOI: 10.5281/zenodo.172729