Metaprotella haswelliana ( Mayer, 1882 )

Takeuchi, Ichiro & Lowry, James K., 2007, Description of Metaprotella haswelliana (Mayer, 1882) (Crustacea: Amphipoda: Caprellidae) from Western Australia with designation of a neotype, Zootaxa 1466, pp. 11-18 : 12-17

Metaprotella haswelliana ( Mayer, 1882)

( Figs. 1–3 )

Protella Haswelliana Mayer, 1882: 32 –33, figs. 8–10.— Haswell, 1885: 998 –999.

Metaprotella Haswelliana. — Mayer, 1890: 24 –25(in part).

Metaprotella haswelliana. — Stebbing, 1910: 652.— McCain & Steinberg, 1970: 54 –55.— Lowry & Stoddart, 2003: 25.

Type material. Neotype male, 13.12 mm, WAM C36785, The Channel, Emu Point, Albany, Western Australia among gorgonians, coll. R. Howlett, 27 Feb. 1960, 11– 12 m.

Additional material examined. Five males, 2 mature, 1 premature and 1 immature females, WAM C8480, The Channel, Emu Point, Albany, Western Australia among gorgonians, coll. R. Howlett, 27 Feb. 1960, 11– 12 m.

Two males, AM P30060, Port Phillip Bay, Victoria (38º23’S 144º52’E), sandy sediment, 9 m, stn 985, coll. Fisheries & Wildlife Division, Victoria, 9 Dec. 1971.

Description. Neotype, male (WAM C36785). Body length, 13.12 mm. Head/pereonite 1 concave along dorsal margin, with paired of anteriorly curved dorsal projections, with paired mid-ventral projections; eye large, distinctive. Antenna 1 0.8 x body length; peduncular article 2 longest; peduncular article 3 straight; flagellum 0.4 x peduncular length, with 13 articles, proximal article composed of 3 articles. Antenna 2 slender; about 0.5 x antenna 1 length; peduncle with several feeble setae; flagellum 1/6 [0.17 x] of peduncular length, with 2 articles.

Upper lip notched, forming rounded quadrilateral projections. Mandible left side incisor with 5 teeth; lacinia mobilis with 5 teeth; accessory setal row with 3 setae; palp article 2 with 7 lateral setae; palp article 3 setal formula 1-13-3-1; right side incisor with 5 teeth; lacinia mobilis with 3 teeth, without trapezoid plate, accessory setal row with 2 row; palp article 2 with 7 lateral setae; small molar flake presence; palp article 3 setal formula 1-15-4-1, with 3 distolateral setae. Lower lip finely setose on inner and outer lobes. Maxilla 1 outer plate with 7 stout apical setal-teeth; palp distal margin with 4 triangular projections, each with a slender or robust seta, 4 robust setae and a row of 4 slender setae. Maxilla 2 inner plate triangular with about 9 apical robust setae; outer plate elongate with about 14 apical setae. Maxilliped basal endite (inner plate) with 2 setae on outer margin; ischial endite (outer plate) oval, 2 x length of inner plate, inner margin blade-like, with many fine setae, with 1 seta on outer margin; palp article 2 setose on inner margin; palp article 3 with 11 distal setae; Pereon. Pereonite 2 with paired anterolateral triangular projection, with paired anteriorly curved mid-dorsal projections, with paired midventral projections, with one anteriorly curved dorsodistal projection; without ventral projection between insertion of gnathopods. Pereonite 3 with rounded anterolateral projection, with paired mid-dorsal projections, with paired midventral projections, with one dorsodistal projection. Pereonite 4 with anterolateral projection; with paired small, mid-dorsal projections. Pereonite 5 with paired tiny anterolateral projection, with paired tiny mid-dorsal projections. Pereonites 6 and 7 fused. Pereonite 3–4 longest. Pereonite 1, 0.31 mm; pereonite 2, 2.20 mm; pereonite 3, 3.14 mm; pereonite 4, 3.09 mm. Pereonite 5, 2.88 mm; pereonites 6–7, 0.92 mm.

Gnathopod 1 carpus and propodus setose; propodus triangular, with 3 rows of submarginal setae on distal part (near anterior margin), palm begins 1/4 along posterior margin, palm smooth, with 1 robust seta near corner of palm, dactylus curved. Gnathopod 2 begins 1/5 along anterior margin; coxa vestigial; basis subequal in length to pereonite 2, with small projection with 2 setae near distal margin; ischium without distolateral projection; carpus 0.1 x propodus length; propodus ovoid, large, length 1.5 x width, with large dorsodistal triangular projection near apical end, and with small dorsodistal triangular projection on middle part; palm proximal projection with 1 robust (grasping) seta, margin convex, minutely serrate, with two triangular projections distally, with large midpalmar spine, with deep, narrow sinus, with broad well developed distal shelf with 3 small projections.

Gill 3 length 1/3 of corresponding pereonite, distal part curved posteriorly. Pereopod 3 very slender; pereonite article 1 with 5 distal setae and about 6 lateral setae. Gill 4 length 1/4 of corresponding pereonite, distal part curved posteriorly. Pereopod 4 very slender; pereonite article 1 with 5 distal setae and about 8 lateral setae.

Pleon. Uropod 1 ramus length about 3– 4 x width, 3– 4 x peduncular length. Uropod 2 ramus vestigial. Telson with a pair of setae.

Female (sexually dimorphic characters). Female "B" (ex. WAM C 8480), 7.58 mm. Head/pereonite 1 without mid-ventral projection. Antenna 1 about 0.5 x body length; flagellum with 12 articles. Pereonite 2 with midlateral projection, without paired midventral projections, without distodorsal projection. Pereonite 3 without paired midventral projections, with triangular dorsodistal projection. Pereonite 1, 0.52 mm; pereonite 2, 1.40 mm; pereonite 3, 1.50 mm; pereonite 4, 1.40 mm; pereonite 5, 1.80 mm; pereonites 6–7, 0.74 mm. Pereonite 5 longest. Gnathopod 2 propodus length 2.2 x width, with small triangular projection near apical end; palm with tiny midpalmar spine, with tiny sinus, without distal shelf, without distal projections. Confirmed distribution

Emu Point, Albany, Western Australia, and Port Phillips Bay, Victoria.

Remarks. Metaprotella haswelliana was first described as Protella Haswelliana by Mayer (1882), based on an immature male and female which were sent to him by Haswell. Mayer (1882) provided the figures of the abdomen of male, a lateral view of a mature female, and gnathopod 2 plus a brief description. The type locality of the specimens was referred as Port Jackson ( Mayer 1882). Haswell (1885) translated the description of Mayer (1882) with a note that "I have only found this species in Port Jackson". Moreover, Mayer (1890) noted the locality of M. haswelliana as Port Jackson and Mayer (1903; p. 143) listed M. haswelliana in the Sydney area (Port Jackson and Broken Bay). Later, the type locality of the present species was referred to as " Australia " by McCain and Steinberg (1970) without explanation. In addition to M. haswelliana from Australia, Mayer (1890) described Metaprotella haswelliana f. taprobanica Mayer, 1890 from Pamban Bridge, India.

McCain and Steinberg (1970) gave the location of type material of Metaprotella haswelliana as Universitetets Zoologiske Museum (= Zoologisk Museum), Copenhagen. However, the type of M. haswelliana was not found in the Zoologisk Museum (N.L. Bruce personal communication), although "the cotype" of " Metaprotella Haswelliana f. taprobanica Mayer, 1890 " was certainly deposited at the Zoologisk Museum, Copenhagen. Moreover, no specimens of M. haswelliana could be found during field surveys along the coast of New South Wales conducted during the 1995/96 austral summer, or in the crustacean collection of the Australian Museum (see Springthorpe & Lowry 1994; Takeuchi & Lowry in prep.).

During a visit by the first author to the Western Australian Museum, Perth, Western Australia, 10 specimens of M. haswelliana were found, including large mature males and ovigerous females. All these specimens were collected from Emu Point, Albany, southern coast of Western Australia on 27 February, 1960. The ovigerous female specimens from Albany, Western Australia possess the same distinct characters as shown and/or described in Mayer (1882) in the formation of projections on body somites, and the presence of a small dorsodistal triangular projection near apical face of lateral palm of gnathopod 2. Since characteristics of large mature males are usually described for the taxonomic studies of the Caprellidea sensu stricto, detailed figures and description are provided for the largest male from Albany, Western Australia. Since all specimens of M. haswelliana which we found had lost pereopods 5 to 7 prior to our examinations, additional material will be required to complete the species diagnosis. Using the new figures made for the present study, two small males collected from Port Phillips Bay, Victoria could be identified as M. haswelliana .

Metaprotella haswelliana was not recorded in Guerra-García (2004) which dealt with 26 species of the caprelloids collected from King George Sound, Western Australia to the Arafura Sea, Northern Territory of the Australia. Thus, the finding of M. haswelliana from Albany, Western Australian and Port Phillip Bay, Victoria with the old records from Port Jackson, Broken Bay (see McCain & Steinberg, 1970), New South Wales ( Mayer 1882, 1890, 1903; Haswell 1885) suggests that M. haswelliana might be endemic to the Flindersian Providence and adjacent areas along the Australian southern coast ( Poore 1994). The changes of environmental conditions during the last century might have caused the disappearance of M. haswelliana from the marginal areas of its distribution, including the Sydney area.

A specimen of Metaprotella haswelliana f. taprobanica labeled as cotype (CRU-2085) in the Zoologisk Museum, Copenhagen, a probable male, is 3.65 mm in body length, which is less than one-third the size of the described specimen of Metaprotella haswelliana from Western Australia. Several features of gnathopod 2 and pereonite 3 readily distinguish M. haswelliana f. taprobanica from M. haswelliana from Western Australia: 1) basis of M. haswelliana f. taprobanica forms a smooth dorsal line, in contrast to a distinct projection with setae from 1/3 of apical end on the dorsal surface in M. haswelliana from Western Australia; 2) in M. haswelliana f. taprobanica the dorsal part of pereonite 3 forms a smooth line, rather than paired mid-dorsal projections and one posterodistal projection in M. haswelliana . These features are almost entirely in agreement with those in Mayer (1890), indicating that M. haswelliana f. taprobanica is a different species from M. haswelliana from Western Australia. However, the type specimen was recorded as 10 mm in body length and deposited at "Museum zu Göttingen” by Mayer (1890). In view of the small size of the “cotype”, redescription of “ M. haswelliana f. taprobanica” should await discovery of larger, more mature specimens.

Figures

FIGURE 1. Metaprotella haswelliana (Mayer, 1882), Albany, Western Australia. Neotype, male; a, lateral view. Female “ B ”; b, lateral view. Scale 0.10 mm.

FIGURE 2. Metaprotella haswelliana (Mayer, 1882), Albany, Western Australia. Neotype, male; a, upper lip; b, left mandible; c, right mandible; d, lower lip; e, maxilla 1; f, maxilla 2; g, maxilliped. Scale 0.10 mm. Note that only 4 of 5 teeth on the incisor of the left mandible are visible in the figure; the fifth tooth is almost overlapped by the others.

FIGURE 3. Metaprotella haswelliana (Mayer, 1882), Albany, Western Australia. Neotype, male; a, flagellum of antenna 2; b, gnathopod 1; c, gnathopod 2; d, gill 3 with pereopod 3; e, gill 4 with pereopod 4; f, pereopod 3; g, pereopod 4; h, abdomen (ventral view). Female “ B ”; i, gnathopod 2; j, abdomen (lateral view). Scale: a, f – h, j = 0.10 mm, b – e, i = 0.50 mm.