Phylladiorhynchus pusillus ( Henderson, 1885 ),
Schnabel, Kareen E. & Ahyong, Shane T., 2019, The squat lobster genus Phylladiorhynchus Baba, 1969 in New Zealand and eastern Australia, with description of six new species, Zootaxa 4688 (3), pp. 301-347: 329-334
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|Phylladiorhynchus pusillus ( Henderson, 1885 )|
Galathea pusilla Henderson, 1885: 407 (Twofold Bay, Australia, 275 m).— Henderson, 1888: 121, pl. 12, figs. 1, 1a, 1b ( Twofold Bay , Australia, 275 m) .— Whitelegge, 1900: 185 (off Bondi , New South Wales, 91 m) .— Grant & McCulloch, 1906: 49, pl. 4, figs. 5, 5a (part, Port Phillip Heads , Victoria) .
Phylladiorhynchus pusillus .— Davie, 2002: 66.— Poore, 2004: 238, fig. 66b (compilation, key).— Poore et al., 2008: 22 (SW Australia, 95–439 m) (part).— Rowden et al., 2010, tab. 3 (in part).
Not Galathea pusilla .— Thomson, 1899: 193, pl. 21, fig. 7 (Whanganui, Cook Strait, Paterson Inlet, 14.6 m) (= P. australis n. sp.).— Chilton, 1906: 267 (Channel Islands, Auckland, 46 m) (= P. australis n. sp.).— Grant & McCulloch, 1906: 49 (part, Mast Head Island specimen = P. spinosus n. sp.).— Chilton, 1911: 303 ( New Zealand) (= P. australis n. sp.).— Borradaile, 1916: 92 (off Three Kings Islands and off North Cape, 183– 128 m) (= P. australis n. sp.).— Hale, 1927: 80 (South Australia, 75 fathoms) (= P. australis n. sp.).— Tirmizi, 1966: 175, fig. 1 (= P. ikedai ( Miyake & Baba, 1965)) .
Not Phylladiorhynchus pusillus . — Miyake & Baba, 1967: 234, fig. 6 (East China Sea, 102–196 m) (different species, undetermined).— Haig, 1973: 282 (S of Cape Everard (Victoria), S and SW of Mt Cann (Victoria) and off St. Helens Point, Tasmania, 110–183 m) (= P. nui n. sp.).— Baba, 1991: 486–487, fig. 4e, f (different species, undetermined).— Baba et al., 2009: 287–289, figs. 263, 264 (different species, undetermined).— Lee et al., 2019: 730, figs. 3, 4 (different species, undetermined).
Records requiring verification:
Galathea pusilla .— Guiler, 1952: 36 (D’Entrecasteaux Channel, Tasmania).—Miyake, 1965: 635, fig. 1044 (no record).— Zarenkov, 1968: 177, fig. 22 (Victoria, Australia, 110 m).— Lewinsohn, 1969: 116 (no record).
Phylladiorhynchus pusillus .— Baba, 1969: 4 (Sagami Bay, 200–300 m).— Baba, 2005: 201, 305 (key, synonymies, Kei Islands and Japan (Sagami Bay and W of Nagasaki), 146–549 m).
Type material. LECTOTYPE: NHMUK 1888View Materials:33 ( Henderson, 1885), male (3.0 mm), Challenger Stn. 163A, Twofold Bay , New South Wales, Australia, 36.98°S, 150.33°E, 150 fathoms (274 m), 4 Apr 1874.GoogleMaps
Other material. Kermadec Islands, New Zealand: NIWA 118725View Materials, 6 males (2.0– 3.2 mm), 8 females ov. (2.3–2.7 mm), Stn. TAN1612/77, Macauley Island, 30.222–30.228°S, 178.397–178.397°W, 72–101 m, 29 Oct 2016GoogleMaps . NIWA 135602View Materials, 2 males (2.7, 3.5 mm), Stn. TAN 1612/97, Macauley Island, 30.247–30.248°S, 178.384–178.380°W, 125– 136 m, 31 Oct 2016GoogleMaps . NIWA 10633View Materials, 1 female (2.0 mm) , NZOI Stn. K 838, Macauley Island , 30.263°S, 178.395°W, 200 m, 28 Jul 1974GoogleMaps . NIWA 43003View Materials, 1 male (1.5 mm) , NZOI Stn. K 855, Cheeseman Island , 30.553°S, 178.527°W, 125 m, 30 Jul 1974GoogleMaps . NIWA 21207View Materials, 4 males (1.7–3.0 mm) , NZOI Stn. K 797, north of L’Esperance Rock , 31.347°S, 178.820°W, 55 m, 19 Jul 1974GoogleMaps . AWMM MA125787View Materials (ex NIWA 135601View Materials), 2 males (3.5, 3.7 mm), 2 females (2.0, 2.3 mm), Stn. TAN 1612/106, L’Esperance Rock, 31.364–31.367°S, 178.759–178.758°W, 90–109 m, 01 Nov 2016GoogleMaps . AWMM MA30532, 1 male (not measured), K 2011-2-1 , W side South Meyer Island 29.247°S, 177.882°W, 21 m, among algae, 12 May 2011GoogleMaps . AWMM MA30533, 1 male (cl 1.8 mm), K 2011-29-1 , Boat Cove, Raoul Island , 29.273°S, 177.927°W, 10 m, 15 May 2011GoogleMaps . AM P88923View Materials, 1 specimen (1.4 mm), K 2011-23-4 , Milne Rocks, Raoul Island , 29.282°S, 177.903°W, vertical rock wall, rocks, cobble, coarse sand & turfing algae, 21 m, 15 Jul 2011GoogleMaps . AWMM MA30534, 1 female (cl 2.2 mm), K 2011-77 - 2, W side Cheeseman Island 30.535°S, 178.570°W, 24 m, 23 May 2011GoogleMaps .
Bay of Islands: NIWA 135611View Materials, 1 female (2.5 mm), Stn . TAN0906 /130, 34.555–34.558°S, 173.160–173.159°E, 107– 105 m, 12 Jul 2009GoogleMaps . NIWA 56259View Materials, 2 females (2.7, 2.8 mm), Stn . TAN0906 /140, 34.571–34.576°S, 173.209– 173.213°E, 117–120 m, 13 Jul 2009GoogleMaps . NIWA 135612View Materials, 1 female (2.3 mm), Stn . TAN0906 /236, Bay of Islands , 34.850– 34.850°S, 173.905–173.898°E, 134– 132 m, 19 Jul 2009GoogleMaps . NIWA 57391View Materials, 1 male (3.4 mm), 2 females (3.0, 3.1 mm), Stn . TAN0906 /235, 34.876–34.879°S, 173.916–173.910°E, 117– 114 m, 19 Jul 2009GoogleMaps . NIWA 55443View Materials, 2 females (3.5, 3.9 mm), Stn . TAN0906 /81, 34.879–34.877°S, 173.917–173.913°E, 115– 112 m, 08 Jul 2009GoogleMaps . NIWA 57503View Materials, 3 males (3.0, 3.0, 4.4 mm), Stn . TAN0906 /240, 34.979–34.980°S, 173.998–174.002°E, 85–93 m, 19 Jul 2009GoogleMaps . NIWA 55302View Materials, 1 female (2.3 mm), Stn . TAN0906 /68, 35.005–35.005°S, 174.060–174.055°E, 110– 108 m, 08 Jul 2009GoogleMaps . NIWA 55202View Materials, 1 male (2.8 mm), Stn . TAN0906 /60, 35.141–35.137°S, 174.290–174.289°E, 103–104 m, 07 Jul 2009GoogleMaps . NIWA 115200View Materials, 1 male (3.3 mm), Stn . TAN0906 /25, 35.553–35.548°S, 174.553–174.553°E, 57– 57 m, 05 Jul 2009GoogleMaps .
Hauraki Gulf: NHMUK 1912View Materials: 11.5.61 –68 (part), 3 males (2.7, 2.8, 3.4 mm), 1 female (3.1 mm) .
New South Wales, Australia: AM P76215View Materials, 1 male (5.3 mm), NSW3083, SE of Kilcare , 33.542°S, 151.374°E, 114 m, rocky reef, from bryozoan, coll. K. Attwood, 2 May 2007GoogleMaps . AM G2387, 1 male (2.1 mm), 1 female (2.8 mm), 8–9.5 km off Coogee , “off Bondi”, Thetis Stn. 44, 33.95°S, 151.358°E, 91 m, fine sand, coll. E.R. Waite, 15 Mar 1898GoogleMaps . AM P86067View Materials, 1 male (1.7 mm), 1 female (2.4 mm), K 80-07-02 , SE of Tathra Head , 36.75–36.80°S, 150.03– 150.05°E, 64 m, trawl, 10 Jun 1980GoogleMaps . AM P89921View Materials, 1 male (1.7 mm) , RV Southern Surveyor Stn. SS05/94/119, E of Disaster Bay, 37.310°S, 150.065°E, 81–82 m, benthic sled, 2 Sep 1994GoogleMaps . AM P89915View Materials, 3 males (1.9, 2.3, 2.5 mm), Stn. SS05/94/127, E of Disaster Bay, 37.315°S, 149.993°E, 24–30 m, benthic sled, 2 Sep 1994GoogleMaps . NHMD-87715, 3 males (1.7, 1.7, 2.5 mm), 1 female (2.3 mm), Disaster Bay , FIS Endeavour, 30–40 fm (55–73 m), sand, mud, trawled, 1 Oct 1914 , coll. Th. Mortensen. AM P89924View Materials, 1 male (2.0 mm), 3 males (1.5–3.0 mm), 4 females (1.7–2.1 mm), 3 females (2.8, 3.0, 3.3 mm), Stn. SS05/94/94, Gabo Island, 37.585°S, 149.722°E, 25 m, trawl, 30 Aug 1994GoogleMaps .
Victoria, Australia: AM G5618, 1 male (4.6 mm), Port Philip Heads , 37.967°S, 144.9°E, coll. F. E. Grant.GoogleMaps AM G5744, 1 male (4.9 mm), 2 females ov. (3.9, 4.1 mm), Port Philip Heads , 37.967°S, 144.9°E, coll. F. E. Grant.GoogleMaps AM P89899View Materials, 1 male (2.3 mm) , RV Southern Surveyor Stn. SS05/94/59, Bass Strait, E of Seal Islands, 38.942°S, 148.322°E, 80–85 m, 27 Aug 1994GoogleMaps . AM P89900View Materials, 1 male (2.3 mm), Stn. SS 05/94/60, E of Seal Islands , Bass Strait, 38.985°S, 148.527°E, 125 m, 27 Aug 1994GoogleMaps .
South Australia: SAM C9974View Materials, 1 female (3.1 mm) , Stn. DCE_100, du Couedic Canyon, 36.336°S, 136.623°E, 106 m.
Western Australia: MV J55116View Materials, 2 males (2.0, 2.7 mm), Stn. SS10/2005/120, off Carnarvon , 24.619°S, 112.666°E, 100– 100 m, coll. G. C. Poore, 7 Dec 2005GoogleMaps . MV J55113View Materials, 1 female ov. (2.5 mm), 1 female (2.6 mm), 6 males (2.7–3.4 mm), Stn. SS10/2005/102, off Kalbarri , 27.813°S, 113.311°E, 96–98 m, coll. G. C. Poore, 5 Dec 2005GoogleMaps . MV J55114View Materials, 1 female ov. (2.9 mm), 1 male (3.0 mm), Stn. SS 10/2005/082, Jurien Bay , 29.803–29.804°S, 114.439–114.436°E, 85–92 m, 2 Dec 2005GoogleMaps . MV J55117View Materials, 5 males (3.0– 3.9 mm), Stn. SS10/2005/002, off Two Rocks , 31.724°S, 115.244°E, 102 m, coll. R. S. Wilson, 18 Nov 2005GoogleMaps . MV55121, 1 male (2.9 mm), Stn. SS10/05/014, off Bunbury , 33.036–33.038°S, 114.820–114.813°E, 95–99 m, 20 Nov 2005GoogleMaps . MV J55120View Materials, 4 females ov. (2.1–3.1 mm), Stn. SS10/2005/15, off Mentelle , 33.98°S, 114.734°E, 97– 96 m, coll. R. S. Wilson, 21 Nov 2005GoogleMaps .
Diagnosis. Rostrum lateral margins convex; subapical spines present. Carapace with 4 epigastric spines of which outermost may be present as a granule and much smaller than inner pair (rarely with 6 spines); anterior metagastric ridge scale-like, medially interrupted. Abdominal tergite 3 usually without posterior transverse ridge. Thoracic sternite 3 anterior margin convex, median projection absent. Antennular article 1 with 5 spines: distomesial spine over-reaching lower distolateral spine, slightly to distinctly overreached by upper distolateral and first lateral spines. Antennal article 1 mesial process not reaching level of second lateral antennular spine; article 2 distolateral and distomesial spines subequal; article 3 with distinct distomesial spine. Maxilliped 3 merus with 1 prominent spine on flexor margin. P2–4 dactylus extensor margin without upright spines at bases of movable spines.
De s cription. Carapace: Length 0.9–[1.0] × width; transverse ridges with dense short setae, and few scattered, longer, iridescent setae. Gastric region with 4 transverse ridges: epigastric ridge medially interrupted, with 2 (rarely 3) pairs of spines in transverse row, innermost pair always prominent, largest, outer pair(s) prominent to obsolescent, sometimes indicated by minute granule; protogastric ridge uninterrupted and extending laterally to carapace margin; mesogastric ridge interrupted laterally by cervical groove; metagastric ridge medially interrupted and forming 2 arches, laterally interrupted by the cervical groove, laterally scale-like and continuing uninterrupted to lateral margin of carapace. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove, followed by 2 complete, uninterrupted ridges, intervened by 3 interrupted ridges. Lateral margins medially convex, with 7 spines: 2 spines in front of (anterolateral, hepatic) and 5 spines behind anterior cervical groove (3 anterior branchial spines, 2 posterior branchial spines). Anterolateral spine well-developed, reaching lateral orbital spine, size subequal. Hepatic spine small, set slightly mesially from lateral margin. Anterior branchial spines subequal in size. Posterior branchial spines with first spine subequal to anterior branchial spines, second smaller. Rostrum length 0.4–0.6 [0.5] × pcl; length-width ratio [1.0]–1.3; distance between basal pair of rostral spines about 0.3 × carapace width; dorsal surface slightly concave; lateral margin distinctly convex, with distinct pair of sub-apical spines. Pterygostomian flap with sharp anterior spine and few small, scattered granules at upper margin near linea anomurica; entire surface with series of broken and continuous striae.
Thoracic sternum: Sternal plastron as wide as or slightly wider than long (length-width ratio [0.8]–1.0); lateral margins divergent posteriorly. Sternite 3 1.7–[2.1] × length; anterior margin convex and minutely serrated; anterolateral margins with broad granule or square.
Abdomen: Tergite 2 with 2 uninterrupted transverse ridges; tergite 3 usually with anterior ridge only, rarely with posterior ridge; tergite 4 with anterior ridge only, remainder smooth, without elevated ridges.
Eye: Eye length about 1.2 × width, peduncle distally setose, slightly expanded proximally, with few short transverse striae on lateral surface; cornea not dilated.
Antennule:Article 1 with 5 well-developed distal spines, distomesial spine well-developed, over-reaching lower distolateral spine; paired distolateral spines present; proximal lateral spine strongly developed.
Antenna: Article 1 with prominent, broad mesial process, distally overreaching peduncle. Article 2 with subequal distal spines, reaching midlength of article 3. Article 3 with distinct mesial spine, anterolaterally squared (unarmed). Article 4 unarmed.
Maxilliped 3 (Mxp3): Ischium with pronounced distal spines on both flexor and extensor margin; crista dentata with regular row of spines along entire margin. Merus slightly shorter than ischium at midline, with strong distal spines on extensor margins, subequal in size to spine at midlength on flexor margin; otherwise unarmed.
Cheliped: Length 2.7–4.7 [3.8] × pcl (males), 2.9–3.5 × pcl (females), larger specimens generally with longer chelipeds; subcylindrical, spiny, setation variable, ranging from densely plumose to sparse. Ischiomerus 1.1–1.9 [1.5] × pcl, 1.5–[2.4] × carpus length; with rows of spines, lateral and distal spines strongest. Carpus with rows of spines except for ventral surface, 1 or 2 lateral spines most prominent. Palm 0.7–[1.5] × carpus length, length-width ratio 1.6–3.2 [2.5], with 4 parallel rows of spines (2 mesial, 1 at about dorsal midline, 1 close to lateral margin, with 1 or 2 spines reaching onto proximal portion of fixed finger. Dactylus 0.6–[0.9] × palm length; usually with 1 distinct proximal spine laterally, 1 or 2 additional small spines in specimens with large chelipeds; surface with short setiferous striae and some scattered granules in large specimens; distally with row of spines along curved margin; tip excavated.
Walking legs (P2–4): Relatively robust, subcylindrical, moderately setose and spinose. Merus successively shorter posteriorly (P2 merus 1.1–1.2 length of P3, P3 merus 1.1–1.2 × length of P4 merus). P2 merus about threefourths pcl; 1.2–1.3 × P2 propodus length; length 4–5 × width. P3 merus 1.0–1.2 × P3 propodus length; length 4–5 × width. P4 merus 0.9 × P4 propodus length; length 3.4–4.0 × width. Extensor margin of P2 and P3 with regular row of spines, proximally diminishing, with prominent distal spine; P4 extensor margin irregular but unarmed; distally unarmed; ventral margins irregular and with strong distal spine on all legs; P4 lateral surface with median row of small spines, absent on P2 and P3. Carpus with 2 or 3 spines on extensor margin on P2–3, irregular but unarmed on P4; distal spine prominent on all legs; 2 or 3 spines along row below extensor margin on lateral surface on all legs; flexor margin unarmed. P2–4 propodus length 4.5–6.0 × height [loose leg of syntype slightly stouter at 4.3]; extensor margin with 3–5 proximal spines on P2–3, typically 2 on P4; flexor margin with 3–5 slender movable spines in addition to distal pair. Dactylus 0.6–0.7 × propodus length, ending in incurved, strong, sharp spine; flexor margin with 5–7 movable spines, otherwise unarmed.
Size. Male pcl 1.5–5.3 mm, female pcl 2.0– 3.9 mm, ovigerous female pcl ≥ 2.3 mm.
Colour in life. Unknown.
Parasites. Five specimens, a 3.1 mm female from South Australia (SAM C9974), a 2.4 mm female from New South Wales (AM P86067View Materials), a 2.3 mm male from Victoria (AM P89899View Materials) and a 2.6 mm female and 3.0 mm male from Western Australia (MV J5513) have kentrogonid rhizocephalan externae under the abdomen.
Genetic data. A specimen each from three samples (NIWA 57503, Bay of Islands, and NIWA 135601 and 135602 from the Kermadec Islands) has been sequenced for COI ( Table 1).
Di s tribution. Confirmed from southeastern, southern and western Australia (New South Wales, Victoria, Tasmania, South Australia), and the northern New Zealand mainland and Kermadec Ridge, 10– 274 m. The type record remains the deepest record for this species (274 m), although more typically, collections were made between 30 and 130 m depth.
Remarks. Phylladiorhynchus pusillus was formerly considered widespread in the Indo-West and Eastern Pacific ( Baba et al. 2008), but it is here confirmed only from New Zealand and temperate Australian waters. The majority of the specimens previously identified as P. pusillus in New Zealand and southeastern Australia belong to two new species, P. australis n. sp. and P. nui n. sp., and differences are discussed under those species above. Several records within the region remain to be verified: specimens reported by Guiler (1952) and Zarenkov (1968) could not be located in collections. Specimens examined from Western and South Australia reported by Poore et al. (2008) conform in all aspects and are identified here as P. pusillus s.s. One specimen contained in sample MV J55117View Materials and three further samples not listed differ from all species reported here and require further study.
Records of P. pusillus from outside New Zealand and Australian waters region remain to be verified, but it seems likely that P. pusillus is restricted to the temperate southwestern Pacific and eastern Indian oceans. Figures of material reported as P. pusillus from Taiwan ( Baba et al. 2009: figs. 263, 264), the East China Sea ( Lee et al. 2019: figs. 3, 4) and New Caledonia ( Baba 1991: fig. 4e) all show a biconcave anterior margin of thoracic sternite 3, indicating that these are not referable to P. pusillus sensu stricto, but belong to other species. Two nominal species formerly placed in the synonymy of P. pusillus ( Galathea integra Benedict, 1902 , Japan; and Galathea lenzi Rathbun, 1907 , Chile) will probably also prove to be separate valid species and are currently under study by Rodríguez-Flores (pers. com.?).
Henderson (1885) described P. pusillus based on a male and two female syntypes, all in poor condition. The largest syntype, the male, is herein designated as the lectotype. The lectotype, unfortunately, has the anterior portion of the carapace fractured and only a single walking leg, presumably the left P3, remaining. Nevertheless, it matches other specimens collected off southeastern Australia (including near the type locality) that help confirm diagnostic characters for this species. Comparing the Australian lectotype with material from New Zealand, the appearance and morphometrics overlap nearly entirely. In some measurements, the single specimen appeared to be at one or the other extreme of the range (e.g., proportions of the rostrum, thoracic sternite 3 and some measurements of the chelipeds) but this is considered natural variation. Despite specimen damage, the diagnostic features of P. pusillus are clearly preserved in the lectotype: the medially broken metagastric ridge that appears as four convex striae across the carapace, a distinctly convex lateral rostral margin, the anteriorly rounded sternite 3, and the distinct mesial spines on antennal articles 2 and 3.
Variation is evident in the ornamentation of abdominal tergite 3. The majority of specimens have only a single transverse ridge on tergite 3, but a distinct posterior transverse ridge is also present in the largest specimen examined (male, 5.3 mm, AM P76215View Materials). Two other relatively large specimens (females, 3.0, 3.3 mm, AM P89924View Materials) from off Gabo Island, near the type locality, also have a posterior transverse ridge on tergite 3, albeit indistinct. The specimens otherwise agree well with other specimens of P. pusillus .
The typical two pairs of epigastric spines, which have to date been the primary recognition features of P. pusillus , exhibit previously unreported allometric variation. In small specimens, one or both of the outermost spines are sometimes yet to be fully developed, present only as a small granule. In the smallest male (NIWA 43003, 1.5 mm), the spines are very difficult to detect, even under highest magnification. Similarly, records of P. integrirostris from the Kermadec Islands ( Ahyong 2015), based on minute specimens (≤ 2.2 mm), proved referable to P. pusillus in which the outer epigastric spines were as yet undeveloped, being present only as a minute granule. At the other extreme, six epigastric spines are occasionally present as in a 2.8 mm female (AM P89924View Materials) and as figured by Poore (2004: fig. 66b). Despite the variation in epigastric spination in some specimens of P. pusillus , the species can be recognised at all sizes by the anteriorly convex rather than biconcave or medially emarginate thoracic sternite 3.
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Phylladiorhynchus pusillus ( Henderson, 1885 )
|Schnabel, Kareen E. & Ahyong, Shane T. 2019|
|Grant, F. E. & McCulloch, A. R. 1906: 49|
|Whitelegge, T. 1900: 185|
|Henderson, J. R. 1888: 121|
|Henderson, J. R. 1885: 407|
|Poore, G. C. B. & McCallum, A. & Taylor, A. C. 2008: 22|
|Poore, G. C. B. 2004: 238|
|Davie, P. J. F. 2002: 66|
Phylladiorhynchus cf. pusillus
|Ahyong, S. T. 2007: 42|
|Lewinsohn, C. 1969: 116|
|Zarenkov, N. A. 1968: 177|
|Guiler, E. R. 1952: 36|