Apseudomorpha drummi Morales-Núñez & Heard & Bird 2019, sp. nov.
Creators: name: Morales-Núñez, Andrés G.
name: Heard, Richard W.
name: Bird, Graham J.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Tanaidacea
Metapseudidae
Apseudomorpha
Apseudomorpha drummi

description: Apseudomorpha drummi sp. nov.
(Figs 2 ̄9)
Material examined. Type material. Holotype— ovigerous ♀, TL 1.7 mm, (UF Arthropoda 49366), Stn BIZ-484 (Biocode No. MBIO40746; BMOO-14503: UF: Arthropoda: 28959), (-17.4824; -149.824), depth 1–2 m, lagoonal patch reef (in coral rubble/ Halimeda /green tufting algae), collector Charlotte Watson, November-01-2010, Mo‘orea Island, mouth of Cook's Bay.
Paratypes — Non-ovigerous ♀, TL 1.8 mm, (UF Arthropoda 49367), Stn BIZ-484 (Biocode No. MBIO40746; BMOO-14503: UF: Arthropoda: 28959), same collection data as holotype.— Two non-ovigerous ♀♀ (with oöstegites), TL 1.5 mm (GCRL 06599) and 1.7 mm (AF Arthropoda 49368), Stn BIZ-288 (Biocode No. MBIO30742; BMOO-10893; UF: Arthropoda: 24615), (-17.48968; -149.82587), depth 1–2 m, fringing reef (in rubble), collectors Kristine White, Sharein El-Tourky, and James Thomas, December-15-2009, Mo‘orea Island, Gump reef.—Non-ovigerous ♀ (with oöstegites), TL 1.8 mm, (USNM 1480633), Stn BIZ-288 (Biocode No. MBIO30681; BMOO-10837; UF: Arthropoda: 24601), (-17.48968; -149.82587), depth 1–2 m, fringing reef (in rubble), collectors Kristine White, Sharein El-Tourky, and James Thomas, December-15-2009, Mo‘orea Island, Gump reef.—Two non-ovigerous ♀♀ (with oöstegites), TL 2.2 mm (GCRL 06600) and TL 2.1 mm (USNM 1480634), and one adult ♂, TL 1.6 mm, (AF Arthropoda 49369), Stn BIZ-498 (BMOO-14237), (-17.4869; - 149.81824), depth 10–15 m, reef wall, collector Jenna Moore, November-05-2010, Mo‘orea Island, Cook's Bay Hotel, opposite Gump Station.—Ovigerous ♀, TL 1.4 mm, (USNM 1480635), Stn BIZ-288 (Biocode No. MBIO30683; BMOO-10839; UF: Arthropoda: 24602), (-17.48968; -149.82587), depth 1–2 m, fringing reef (in rubble), collectors Kristine White, Sharein El-Tourky, and James Thomas, December-15-2009, Mo‘orea Island, Gump reef.—Ovigerous ♀ (dissected), TL 1.6 mm, (AF Arthropoda 49370), Stn BIZ-237 (Biocode No. MBIO29351; BMOO-09640), (-17.59026; -149.83972), depth 2 m, fringing reef (under and on rocks), collectors Sarah McPherson, Kristine White, Sharein El-Tourky, Gustav Paulay, Seabird McKeon, and Chris Meyer, December-06-2009, Mo‘orea Island, Atiha Bay).—Adult ♂, TL 1.8 mm, (USNM 1480636), Stn BIZ-487 (Biocode No. MBIO40726; BMOO-13318; UF: Arthropoda: 28816), (-17.51012; -149.85129), depth 0.5–1 m, collectors Arthur Anker, Charlotte Watson, Gary Poore, and John Slapcinsky, October-31-2010, Mo‘orea Island, E side of Opunohu Bay, about 1 km N of Criobe, near white tower in water.
Additional material —adult ♂ (damaged), TL 1.8 mm, Stn BIZ-487 (Biocode No. MBIO40726; BMOO-13318; UF: Arthropoda: 28816), (-17.51012; -149.85129), depth 0.5–1 m, collectors Arthur Anker, Charlotte Watson, Gary Poore, and John Slapcinsky, October-31-2010, Mo‘orea Island, E side of Opunohu Bay, about 1 km N of Criobe, near white tower in water.—Non-ovigerous ♀ (with oöstegites), TL 1.5 mm,, Stn BIZ-288 (Biocode No. MBIO30676; BMOO-10833; UF: Arthropoda: 24599), (-17.489683; -149.825871), depth 1–2 m, fringing reef (in rubble), collectors Kristine White, Sharein El-Tourky, and James Thomas, December-15-2009, Mo‘orea Island, Gump reef.
Diagnosis. Female. Rostrum convex with broad base. Antennule main flagellum with three articles. Mandible palp article-2 with five setulate setae on inner margin. Labium palp with small spiniform setae on sub-proximal margin. Maxillipedal palp article-1 outer margin with spiniform seta. Pereopod-1 basis with dorso-proximal margin lacking blunt, spiniform process; carpus and propodus with ventral margin having two and four spiniform setae, respectively. Pleonites -2 and -3 with pleura having long distal seta. Pleopods biramous, exopod and endopod each with single long seta.
Male. Cheliped propodus with one simple and one bipinnate spiniform setae on mid-medial margin near articulation of dactylus.
Etymology. Named on honor of our friend and colleague David T. Drumm in recognition of his work on Tanaidacea and other invertebrate groups.
Type locality. Mouth of Cook's Bay (-17.4824; -149.824), Mo‘orea Island, Society Island, French Polynesia.
Distribution. Known from the shallow coastal waters of Mo‘orea Island at depths ranging from 1 to 15 m.
Description. Based on ovigerous ♀ (holotype (UF Arthropoda 49366) and paratype (UF Arthropoda 49370).
Body (Fig. 2). Length 1.7 mm, about 4.1 times ltb.
Cephalothorax (Fig. 2A ̄B). About 25% of TL, shorter than combined lengths of pereonites 1–3, just longer than broad; rostrum convex with broad base, with small denticles and median short trifurcate tip (Fig. 2B); eyelobes well defined, visual elements present. Carapace with simple seta near each ocular lobe and simple seta on each mid-proximal face; branchial region with dorsal red-pigmented area (retained in ethanol).
Pereon (Fig. 2A). About 60% of TL, all pereonites wider than long, all with two simple setae on sub-distal dorsal margin; pereonite-1 wider than others; pereonites 2̄6 longer than pereonite-1, with one small tuberculiform apophysis ending in a seta on each anterolateral margin; pereonite-6 shortest.
Pleon (Figs 2A, C, 8A). About 6% of TL, combined lengths of pleonites 1–5 sub-equal to pereonite-6; all pleonites sub-equal, wider than long, bearing pleopods (Fig. 8A); pleonite-1 laterally rounded with small simple seta (Fig. 2C); pleonites 2–5 epimera with bifid tip (Fig 2C); pleonites 2 and 5 with two (one long and one small) simple setae (Fig. 2C); pleonites 3–4 with one small simple seta (Fig. 2C).
Pleotelson (Figs 2A, C, 8A). About 9% of TL, longer than pereonite-6 (Fig. 2A); dorso-anteriorly with two tubercles, each with two simple setae (Figs. 2A, 8A); antero-laterally with apophysis with bifid tip and bearing a simple seta distally (Fig. 2C); apex with two sub-distal setae (Fig. 8A).
Antennule (Fig. 3A). Longer than cephalothorax. Peduncle with four articles. Article-1 almost four times ltb; inner margin with two (one long and one short) medial and one sub-distal pointed apophyses, with five simple setae; dorsal margin with two (one PSS and one simple) proximal setae, two medial simple setae, and row of three sub-distal setae; outer margin with one short medial apophysis and one long distal apophysis, with two cluster of three PSS each. Article-2 about 1.3 times ltb; inner margin with four simple setae, with dorsal sub-distal row of four simple setae and one PSS; outer distal margin with one PSS. Article-3 slightly wider than long; inner distal margin with simple seta; outer margin with two PSS. Article-4 shorter than broad; inner distal margin with two simple setae; dorsal margin with two simple setae. Outer flagellum with three articles. Article-1 just longer than broad, with outer distal simple seta. Article-2 about1.4 times ltb; inner distal margin with simple seta; outer distal margin with two simple setae. Article-3 about 2.7 times ltb, distally with one PSS, two aesthetascs, and five simple setae of various lengths. Inner flagellum uniarticulate, 3.2 times ltb, distally with two PSS and four simple setae of unequal lengths.
Antenna (Fig. 3B). With eight articles. Article-1 inner margin with mid simple seta and distal expansion; outer margin with distal denticles. Article-2 inner margin with distal apophysis; outer margin with two simple setae; squama present, just longer than article-3, with two distal simple setae of unequal lengths. Article-3 wider than long; inner sub-distal margin with simple seta. Article-4 inner distal margin with one PSS. Article-5 about 1.5 times ltb, longer than article-4, inner distal margin with two long simple setae of unequal lengths and two PSS; outer distal margin with two PSS. Article-6 half-length of article-5; outer distal margin with long simple long seta. Article-7 about 1.6 times ltb, inner distal margin with two simple setae of unequal lengths and one PSS; outer distal margin with simple seta. Article-8 shortest, with three distal setae of various lengths.
Mouthparts: Labrum (Fig. 3C). Shorter than broad, distally setulate. Mandibles (Fig. 3D ̄J). Left mandible incisor with five denticles (Fig. 3D, J); lacinia mobilis broad with three uneven denticles (Fig. 3D ̄E); setiferous lobe with four multi-furcate setae and one simple spiniform seta (Fig. 3D). Right mandible incisor with four uneven denticles (Fig. F̄G); lacinia mobilis bifurcate with several denticles on dorsal margin (Fig. 3F ̄H); setiferous lobe with four multi-furcate spiniform setae (Fig. 3F). Molar process of left and right mandible similar, with grinding surface with well-developed micro-denticles and simple small setae (Fig. 3I). Palp (Fig. 3J) article-1 shortest, inner margin with distal simple seta; article-2, 1.7 times ltb, longest, mid-inner margin with five setulate setae of unequal lengths; article-3 with seven setulate distal setae of different lengths.
Labium (Fig. 4A). Lobe with inner distal margin setose, with two (sub-proximal) and three (distal) denticles on outer margin. Palp oval, outer lobe setulose, with one small spiniform setae on sub-proximal margin and two distal spiniform setae.
Maxillule (Fig. 4B). Inner endite with five setulate distal setae, margins finely setose. Outer endite with eleven (one small) distal spiniform setae and two sub-distal setulose setae, margins finely setose; palp biarticulated with two sub-distal setae and one distal whip-like seta.
Maxilla (Fig. 4C ̄H). Inner and outer margins with three denticles, and outer margin finely setose; outer lobe of moveable endite with two simple setae and six inner pinnate spiniform setae (Fig. 4D); inner lobe of moveable endite with five simple spiniform setae; outer lobe of fixed endite with two bipinnate sub-distal spiniform setae (Fig. 4E) and three trifurcate-plumose spiniform setae (Fig 4F); inner lobe of fixed endite with one bipinnate spiniform seta (Fig. 4G), one inner trifurcate-plumose spiniform seta (Fig. 4H), one bipinnate sub-distal spiniform seta, and row of ~14 basally swollen setae.
Maxilliped (Fig. 4I ̄K). Coxa short and wide. Basis wider than long, with spiniform seta on distal inner margin, and four denticles on outer distal margin. Palp article-1 shortest, distal inner margin with long (passing article-3) simple seta, and distal outer margin expanded distally with spiniform seta; article-2 longest, inner margin finely setulose proximally, with 13 simple setae of various lengths, outer distal margin with strong spine; article-3, inner margin with five simple setae and three inner setulate spiniform setae; article-4, inner margin with seven setulate spiniform setae (Fig. 4J) and one simple seta. Endite (Fig. 4K) with inner margin having two coupling hooks, row of seven basally-swollen setulate setae, four apically bidentate or grooved spiniform setae with outer setulose margin, one sub-distal bipinnate spiniform setae, and four apically long bidentate or grooved spiniform setae; outer margin setulose with small denticles on mid margin.
Epignath. Not recovered.
Cheliped (Fig. 5A ̄D). Basis, 2.0 times ltb; ventral margin with two proximal simple setae, with one spine on mid-margin, and two (one short and one long) sub-distal simple setae; dorsal margin with three simple setae (Fig. 5B). Merus triangular; ventral margin with simple setae sub-distally; mid-outer margin with one simple seta; inner face with two sub-distal simple setae (Fig. 5B). Carpus 3.0 times ltb, as long as basis, widest distally; ventral margin with one small (medial) and two (sub-distal) simple setae; dorsal margin with one sub-distal simple seta. Propodus just longer than broad; outer margin with two (one near articulation of dactylus) simple setae of unequal lengths; dorsal margin with two (one distally) simple setae; inner face with one simple seta and one bipinnate spiniform seta on mid-medial margin near articulation of dactylus (Fig. 5C); fixed finger with three ventral simple setae, with five sub-marginal simple setae on outer incisive margin, claw short; inner face with sub-distal and middorsal (Fig. 5B) bipinnate spiniform setae (Fig. 5D). Dactylus and unguis longer than fixed finger, claw bifid distally; inner face with three bipinnate spiniform setae on sub-distal margin (Fig. 5B).
Pereopod -1 (Fig. 6A ̄C). Coxa with apophysis, with four simple setae. Basis 4.8 times ltb; distoventral margin with one spine and one long simple seta; dorsal margin with sub-proximal PSS and three simple setae. Ischium wider than long, with two simple setae of unequal lengths on distal ventral margin. Merus 2.5 times ltb, widest distally; ventral margin with three simple setae and one sub-distal bipinnate spiniform seta (Fig. 6B); outer margin with sub-distal simple seta; distodorsal margin with one simple seta and one bipinnate spiniform seta; inner face with sub-distal ventral simple seta (Fig. 6C). Carpus 1.3 times ltb, widest distally, ventral margin with two bipinnate spiniform seta; outer margin with two simple setae: distodorsal margin with three simple setae of varying lengths and bipinnate spiniform seta; inner face with two simple setae on ventral margin (Fig. 6C). Propodus twice as long as broad, ventral margin with four bipinnate spiniform seta and two simple setae; outer margin with two (one in the middle and one distal) simple setae; dorsal margin with mid PSS, two (one sub-distal and one distal) bipinnate spiniform seta, and one sub-distal simple seta; inner face with one setulate spiniform seta and one (longer as dactylus and unguis combined) simple seta (Fig. 6C). Dactylus curved, together with unguis shorter than propodus, dactylus longer than unguis; dactylus with two (one in the middle one sub-distal) ventral setae and small sub-distal denticle.
Pereopod-2 (Fig. 6D ̄E). Shorter and more gracile than pereopod-1. Coxa lacking apophysis, with two simple setae (Fig. 6D). Basis almost four times ltb; ventral margin with sub-proximal simple seta and two distal simple setae; dorsal margin with four simple setae. Ischium wider than long, with three simple setae of unequal lengths on distal ventral margin. Merus 1.8 times ltb, widest distally; ventral margin with three simple setae, with two subdistal bipinnate spiniform seta; outer margin with sub-distal medial simple seta; distodorsal margin with simple seta; inner face with sub-distal ventral simple seta (Fig. 6E). Carpus slightly ltb, wider distally; ventral margin with four bipinnate spiniform seta; sub-distal outer margin with two bipinnate spiniform setae; dorsal margin with two sub-distal setae and one distal simple seta. Propodus 2.2 times ltb; ventral margin with four bipinnate spiniform seta and four simple setae; dorsal margin with mid PSS, two (one sub-distal and one distal) bipinnate spiniform setae, and one sub-distal simple seta; inner face with one setulate spiniform seta (Fig. 6C). Dactylus curved, together with unguis shorter than propodus, dactylus longer than unguis; dactylus with small sub-distal denticle and one simple seta.
Pereopod-3 (Fig. 6F ̄G). Similar to pereopod-2 but shorter. Basis with four (one ventral and three dorsal) PSS. Merus shorter.
Pereopod-4 (Fig. 6H ̄J). Basis five times ltb; ventral margin with one PSS, one mid simple seta, and one subdistal simple seta; outer margin with one simple seta; dorsal margin with three sub-proximal PSS and two simple setae. Ischium wider than long, with three simple setae of unequal lengths on mid ventral margin. Merus 1.5 times ltb; sub-distally with three simple setae and two sub-distal bipinnate spiniform setae; outer margin with one medial simple seta. Carpus twice as long as broad; ventral margin with four bipinnate spiniform setae; distal mid-outer margin with simple setae; dorsal margin with one sub-distal simple seta, and one long simple seta and one bipinnate spiniform seta, distally; inner face with seven (six ventral and one mid sub-distally) bipinnate spiniform setae and one mid sub-distally simple seta (Fig. 6I). Propodus 3.4 times ltb; ventral margin with bipinnate spiniform seta; dorsal margin with mid PSS, and row of six sub-distal pectinate setae (Fig. 6J); inner face with row of five sub-distal pectinate setae (Fig. 6I). Dactylus curved, together with unguis shorter than propodus, dactylus longer than unguis; dactylus with two (one in the middle and one sub-distal) ventral setae and small sub-distal denticle.
Pereopod-5 (Fig. 7A ̄B). Similar to pereopod-4 but slightly smaller. Carpus with five bipinnate spiniform setae on ventral margin; sub-distal dorsal margin with a row of four simple setae. Propodus with two bipinnate spiniform setae on ventral margin; outer margin with two simple setae; distodorsal margin with two simple setae and one pectinate seta; inner face with row of five sub-distal pectinate setae (Fig. 7B). Dactylus with two sub-distal simple setae on ventral margin.
Pereopod-6 (Fig. 7C ̄D). Similar to pereopod-5 but slightly longer. Carpus with three bipinnate spiniform seta on ventral margin. Inner face of propodus with row of seven sub-distal pectinate setae (Fig. 7D).
Pleopods (Fig. 7E ̄F). Five similar, biramous pairs. Basal article 7.7 times ltb, longer than both rami, asetose. Exopod slightly longer than endopod, both uniarticulate, both with long plumose seta distally (Fig. 7F).
Uropod (Fig. 7G). Biramous. Basal article about twice as long as broad; inner margin with two distal simple setae of unequal lengths; outer margin with one mid and two sub-distal simple setae of various lengths. Exopod of three articles, longer than endopod articles 1̄2 combined; article-1 small, asetose, shorter than article-2 (the division between article-1 and 2 is often indistinct) with simple distal seta on both margins; article-3 with two simple setae of varying lengths distally. Endopod longer than pleon and pleotelson combined, with five articles; article-1 shorter, asetose; article-3 longest; articles 2̄4 bearing two to three simple setae on distal margins; terminal article with two PSS and four simple setae of unequal lengths distally.
Adult male. Length 1.6 mm. Similar to females except in the size of the chelipeds (paratype, UF Arthropoda 49369).
Cheliped (Fig. 8A ̄F). Robust. Basis slightly wider than long; ventral margin with three (two sub-proximal and one distal) simple setae, and one spiniform seta; dorsal margin with two simple setae. Merus triangular, mid margin with one simple seta; distoventral margin with three simple setae. Carpus broad and short; distoventral margin with a prolongation and one distal simple seta; outer distal margin with four denticles and one simple seta; inner face with series of ~12 ridges, with two simple setae on mid proximal margin, and two simple setae dorsally. Propodus 1.3 times as wide as long; ventral margin with proximal tridentate apophysis, (Fig. 8B), with two simple setae, and mid simple seta; outer margin with one simple seta near to articulation of dactylus; dorsal margin with two (one mid and one distal) simple setae; inner face with ventral simple seta, with one simple seta and two (one simple and one bipinnate (Fig. 8E)) spiniform setae on mid-medial margin near articulation of dactylus; fixed finger short, with three ventral simple setae, with nine sub-marginal simple setae on outer incisive margin; dorsal margin with two denticle and grasping edge with row of ~seven blade-like pectinate setae (Fig. 8C), claw short; inner face with three ventral simple setae, one sub-distal bipinnate spiniform seta, and three mid-dorsal simple setae (Fig. 8D). Dactylus curved, longer than fixed finger, ventral margin with mid-denticle and grasping edge with row of ~six blade-like pectinate setae having finely pectinate or serrate upper margins, claw with bidentate tip for insertion of tip of dactylus (Fig. 8C); inner face with three bipinnate spiniform setae (Fig. 8F) on sub-distal margin.
Intraspecific variation. Apseudomorpha drummi sp. nov. exhibits some degree of variation among the individuals examined during this study (Table 1), such as the number of articles on the antennular outer flagellum observed on non-ovigerous females that varied from 2–3 (Table 1), three being the most common. The presence, however, of two articles was only observed on the left antennular flagellum of a non-ovigerous, female paratype (USMN 01480634). Further, the number of articles on the antennular outer flagellum on males varied from 3–4 (four in paratype, USNM 1480636). The uropods also expressed considerable variation. The number of articles occurring in the exopods of a non-ovigerous females, ovigerous females, and males varied from 2–3 (Table 1). The total length of the exopod in relation to that of the endopod varied from being longer as endopodal article-1 to extending to the mid-length of endopod article-3 (Table 1). In some specimens the right endopod is shorter than left.
Size-distribution. The body sizes of individuals Apseudomorpha drummi measured are presented in Table 1. The non-ovigerous females ranged from 1.5 to 2.1 mm (n=7). Ovigerous females ranged from 1.4 to 1.7 mm (n=3). Adult males varied from 1.6 (Fig. 9) to 1.8 mm (n=3).
Remarks. Apseudomorpha drummi is the fourteenth member of the genus to be described (Table 2, Key). With A. fontainei, A. glebosa, and A. martinicana, it comprises a group of Apseudomorpha characterized by having exclusively long setae on the epimera of the second and fifth pleonites. The new species from Mo‘orea differs from A. fontainei by having (1) the mandibular palp with article-1 having an inner distal spiniform seta (two in fontainei), (2) biramous pleopods (uniramous in fontainei), (3) a uropodal exopod with three articles (two in fontainei), and (4) the uropodal endopod with five articles (seven in fontainei).
Apseudomorpha drummi is distinguished from A. glebosa by (1) presence of two and four spiniform setae on the ventral margin of carpus and propodus of pereopod-1, respectively (three and five in glebosa), (2) pereopod-6 with two ventral bipinnate spiniform setae (four in glebosa), (4) each branch of the pleopods with long setae (one branch with one long seta in glebosa), and (5) uropodal exopod article-1 shorter than endopodal article-1 (longer in glebosa).
* Indicates male known.
Based on the examination of specimens by G.J. Bird referable to Apseudomorpha timaruvia indicates that this species probably belongs in another genus as it differs from the other species of Apseudomorpha, including A. drummi, in having (1) a long apical seta only on the epimeron of pleonite-3, (2) more numerous antennular articles (ca. six inner, nine outer), and (3) a double row of spines on the carpus and propodus of pereopods 1–3. It is retained in the genus pending its complete redescription (G. J. Bird in prep.). Apseudomorpha drummi can be distinguished from the other species of Apseudomorpha in the following identification key.
The members of the genus Apseudomorpha are mostly confined to the Pacific and Indian Oceans (Figure 10); however, Heard et al. (2004) reported and illustrated an apparently undescribed species (“ Apseudomorpha sp. A”) with affinities to the Eastern Pacific species A. glebosa Menzies, 1953, from the Atlantic East Coast of Florida. Later, Guţu (2006, 2009) described A. ortizi from Cuba and A. martinica from Martinique Island. Further, Heard et al. (2009) reported A. glebosa or a very similar cryptic geminate species from coral reefs off the Southeast Caribbean Coast of Costa Rica.
description: Published as part of Morales-Núñez, Andrés G., Heard, Richard W. & Bird, Graham J., 2019, Two new apseudomorphan species (Crustacea: Tanaidacea: Metapseudidae) from Mo'orea Island (Society Islands, French Polynesia) with taxonomic keys, pp. 213-247 in Zootaxa 4564 (1) on pages 216-229, DOI: 10.11646/zootaxa.4564.1.8, http://zenodo.org/record/2588858