Carpias montaguensis, Doti, Brenda Lía & Wilson, George D. F., 2010

Doti, Brenda Lía & Wilson, George D. F., 2010, The genera Carpias Richardson, Ianiropsis Sars and Janaira Moreira & Pires (Isopoda: Asellota: Janiridae) from Australia, with description of three new species, Zootaxa 2625, pp. 1-39 : 6-14

publication ID	https://doi.org/ 10.5281/zenodo.198196
DOI	https://doi.org/10.5281/zenodo.6196445
persistent identifier	https://treatment.plazi.org/id/8F5B152B-D05C-8E7B-FF0A-FF5FFC06FAEC
treatment provided by	Plazi
scientific name	Carpias montaguensis
status	sp. nov.

Treatment

Carpias montaguensis View in CoL sp. nov.

( Figs 1–7 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 )

Etymology. The species is named for the type locality Montague Island, New South Wales, Australia.

Type fixation. Holotype adult 3, 1.47 mm, P.81244, here designated.

Type locality. Montague Island, New South Wales, Australia: 'Northwest Trench', NSW 1775, 36º14.55'S, 150º13.45'E, depth 33 m.

Paratypes. Station NSW 1775 (data for type locality), Hermon Slade Foundation Montague Island Expedition, coll. by G.D.F. Wilson, 24 Mar 2001, among lacy bryozoan colonies at base of trench wall growing in rubble and detritus: BƤ (1.46 mm), P.81245; T3 #5 (1.46 mm), dissected, P.81391; S3 #3 (1.32 mm), dissected, P.81247; J3 #1 (1.05 mm), dissected, P.81246; Ƥ, P.81392 dissected; T3, SEM stub MI135, P.81113; T3, SEM stub MI174, P.81118; BƤ, SEM stub MI175, P.81119; 34 inds (3 1.05–1.67 mm; ƤƤ 1.46–1.60 mm), P.81393.

Other material. Australia, New South Wales, Station NSW 1777 (data for type locality), coll. by A.J.K. Millar & N.Yee, 24 Mar 2001, among Spyridia filamentosa & Zonaria diesingiana (red algae) on rocky substrate: 4 ƤƤ, P.84007.

Batemans Bay region. Burrewarra Point, coll. by A.J.K. Millar & party, 25–27 Oct 2002: 3, P.84008, NSW 1986, east Wall, 35º50.02'S, 150º14.16'E, 25 m, among Curdiea crassa with small amount of Martensia australis ; 1 Ƥ, P.84009, NSW 1993, Gutters, 35º49.82'S, 150º14.08'E, 24 m, among Pachymenia prostrata (alga); 3, P.84010, NSW 1997, Gutters, somewhat inshore, 35º49.87'S, 150º14.08'E, 23 m, among Codium lucasii .

Burrewarra Point, 35º49.81'S, 150º14.01'E, coll. by P. Berents & party, 23 Mar 2004: 3 ƤƤ, P.84011, NSW 2499, 16.5 m, among Sertularia adpressa (hydroid); 23 inds, P.84012, NSW 2500, 20.8 m, dead & live bryozoans cf. Triphyllozoon ; 5 ƤƤ, P.84013, NSW 2513, 20.8 m, bryozoan rubble.

Burrewarra Point, 35º49.78'S, 150º13.96'E, coll. by P. Berents & party, 24 Mar 2004: Ƥ, P.84014, NSW 2518, 16 m, among cf. Triphyllozoon sp. (bryozoa); Ƥ, P.84015, NSW 2521, 13.4 m, among Amathia sp. (bryozoan); 1 3, 4 ƤƤ, P.84016, NSW 2546, 14.1 m, among mixed bryozoan rubble.

Burrewarra Point, coll. by P. Berents & party, 27 Mar 2004: 16 inds (11 ƤƤ, 4 3 & juv.), P.84017, NSW 2614, 35º49.89'S, 150º14.11'E, 20.3 m, among lacy bryozoan cf. Triphyllozoon sp.; 31 inds, P.84018, NSW 2627, 35º50.28'S, 150º14.09'E, 18.5 m, among orange lacy bryozoan cf. Triphyllozoon .

Tollgate Islands, 35º44.83'S, 150º15.42'E, coll. by P. Berents & party, 29 Mar 2004: 4 3, 6 ƤƤ, P.84019, NSW 2643, 7 m, Ecklonia radiata (alga) holdfasts; 1 3, P.84020, NSW 2645, 7 m, chaetopterid tubes in dense mats.

Diagnosis. Eyes large, with more than 10 ocelli. Pereonites 2–4 laterally concave. Pleotelson lateral margin denticles absent; posterior margin broadly rounded, without posterior inflection. Mandible molar distal margin with paired blade-like ridges; palp article 1 simple setae absent. Maxilliped palp article 3 distolateral margin subrectangular, distomedial margin with distinct inflection (in T3 distomedial margin convex). Pereopod I of adult (terminal) male carpus ventral margin proximal to palm approximately linear, slightly sinuous; palm region transverse relative to dorsal margin, with 3 flattened spines, ventral spine largest sharpest and curved; propodus distinctly shorter than carpus, tapering distally, ventral margin with 2 rounded flattened spines; dactylus well developed, with 2 claws. Pereopods II–VII dactylus ventral claw less robust than dorsal claw. Pleopod I of adult male projecting posteriorly, not curved; medial lobe distal margin convex, curving anteriorly and medially. Pleopod II of adult male protopod distal margin setae absent, endopod stylet weakly curved laterally and then reflexed medially.

Description. Pigmentation in preservative light coloured, without spots. Body length of male 1.05–1.67 mm, female 1.35–1.6 mm; length 2.6, 2.7 width (BƤ, 3, respectively), widest at pereonite 3.

Head ( Fig. 1 View FIGURE 1 B, D) Width 1.68 length. Anterior margin in dorsal view linear. Eyes length 0.41 head medial length, posterior margin adjacent to pereonite 1.

Pereonites ( Fig. 1 View FIGURE 1 D). Pereonites 1–7 medial length ratios relative to pereonite 2 (Ƥ, P.81245, males too curved to measure accurately): 0.57, 1.0, 1.1, 0.42, 0.39, 0.71, 0.85, respectively. Pereonites 2–4 laterally concave.

Pleon ( Figs 1 View FIGURE 1 C; 6D). Pleotelson length 0.93 width; lateral margins smooth, forming nearly circular arc; posterior margin broadly rounded, without posterior inflection.

Antennula and Antenna ( Figs 1 View FIGURE 1 A–B, 2A, 6A). Antennula of male length 1.41 head median length, with 11 articles; in female length 1.06 head median length, with 11 articles, article 1 length 1.02 width, article 2 length 1.5 article 3 length. Antenna length 1.18 body length ( Fig. 6 View FIGURE 6 A), articles 1–6 length 0.31–0.35 body length (3), article 5 distinctly longer than articles 1–4, article 5 length 0.96 article 6 length, flagellum with 28 articles (3).

Mouthparts ( Figs 2 View FIGURE 2 B–F, 3A). Mandible left spine row with 6 spines; right spine row with 7 spines; molar distal margin with paired blade-like ridges. Mandible palp length 0.86 mandibular body length, article 1 simple setae absent. Maxillula lateral lobe distal margin with 12 robust denticulate setae. Maxilla lateral lobes with 4 curved denticulate setae. Maxilliped palp article 2 width 1.5 endite width, article 3 distolateral margin subrectangular, distomedial margin with distinct inflection (in T3 distomedial margin convex); endite length 1.48 width, distal margin with 6 fan setae, medial margin with 2 receptaculi.

Pereopod I. Coxa projecting anterolaterally, angular ( Fig. 1 View FIGURE 1 B, D). Pereopod I adult female length 0.52 body length.

Pereopod I of adult (terminal) male ( Figs 3 View FIGURE 3 B–C; 4A–B showing less adult specimens; 6C, E). Length 0.86 body length; basis elongate, longer than bases on posterior pereopods but not projecting past pereonite 4, basis slightly shorter than carpus. Ischium length 0.54 carpus length. Merus length 0.63 carpus length. Carpus setose, robust setae absent, width 0.46 length, ventral margin proximal to palm approximately linear, slightly sinuous, palm region transverse relative to dorsal margin. Propodus length 0.54 carpus length, distal width 0.65 proximal width. Dactylus length 1.08 propodus distal width.

Pereopods II–VII ( Figs 1 View FIGURE 1 A, 4C–D, 6B–C). Pereopod II length 0.5 body length (T3); coxa anterolateral margin rounded. Pereopod IV length 0.65–0.68 body length (T3, J3). Pereopod VII length 0.6 body length.

Pleopods ( Figs 5 View FIGURE 5 A–E, G, 6F). Operculum of female length 0.93 width, distal margin convex but with two lateral indentation at the insertion of the setae, distal margin with few setae (2 setae in indentations). Pleopod I of adult male distal width 0.31 proximal width; dorsal surface stylet guides lateral margin without denticles; lateral lobe distal margin present, single, with spine on medial side, with 5–6 setae; medial lobe without distinct indentation at inner margin of lateral lobe, margin not projecting, medially convex, width 0.07 pleopod (both sides) distal width, with 3 setae, of which 1 setae longer than others. Pleopod II of adult male protopod distal margin setae absent, endopod proximal article width near distal article maximum width, endopod stylet length 0.9 protopod length. Pleopod III exopod distal margin tapering to narrowly rounded tip, length 0.99 endopod and protopod length, articulation between 2 articles absent.

Uropods ( Figs 1 View FIGURE 1 C, 5F, 6B, D). Shorter than pleotelson, length in adult male 0.64–0.84 pleotelson length, longer in adult female, length 0.96 pleotelson length. Protopod length 2.28 width, elongate trapezoidal, proximal width much narrower than distal width. Endopod length 1.26 protopod length, 1.26 exopod length.

Distribution. Montague Island, Burrewarra Point and Tollgate Island (Batemans Bay, Australia), 7–33 m ( Fig. 7 View FIGURE 7 ).

Remarks. Pereopod I of Carpias montaguensis sp. nov. terminal males resemble that of C. brucei ( Monod, 1974) but with some differences: carpus with 3 spines equidistant that decrease in size from distal to proximal; propodus with distal spine larger than proximal one. C. brucei , however, has a carpus with a distinct gap between distal spine and two similarly sized proximal spines, and propodus has 2 similarly sized ventral spines.

Across the species of Carpias , variation in the width of the medial lobe of male pleopod I is worth noting. The medial lobe can be defined as the distal tip of the pleopod I that is medial to the lateral margin of the stylet guide. If the lines illustrated on the pleopod I of many species is indicative of the lateral margin of the stylet guide, then Carpias shows considerable variation in the composition of the pleopod I inner lobe. C. montaguensis sp. nov. is notable in that its medial lobe is limited to a thin strip on the inner margin of the pleopod distal tip.

The distribution of Carpias montaguensis sp. nov. is limited to southern NSW ( Fig. 7 View FIGURE 7 ), where this species appears to favour living among bryozoan colonies or rubble thereof. Of the algal species on which this species occurred, most were prostrate forms, which also would have associated sessile colonies of bryozoans. We did not, however, assess the sessile animals living on the prostrate algae.