Orthoprotella mayeri K.H. Barnard, 1916

Takeuchi, Ichiro & Lowry, James K., 2007, Redescription of Orthoprotella mayeri K. H. Barnard, 1916 (Crustacea: Amphipoda: Caprellidae) from Cape Province, South Africa and description of O. berentsae sp. nov. from New South Wales, Australia, Zootaxa 1632, pp. 37-48 : 38-42

Orthoprotella mayeri K.H. Barnard, 1916

( Figs. 1–3 )

Orthoprotella mayeri K.H. Barnard, 1916: 284 –285.— K.H. Barnard, 1925: 372 –373 (in part).— McCain & Steinberg, 1970: 57 (in part).

Not Orthoprotella mayeri .— Lowry & Stoddart, 2003: 27 (= Orthoprotella berentsae sp. nov.). Not Orthoprotella sp. Mayer, 1903: 36, pl. 1, figs. 25–26, pl. 6, figs. 43–44, 46, pl. 9, figs. 15 (= Orthoprotella berentsae sp. nov.).

Type material. Holotype, male, SAM-A90, Glendower Beacon near Port Alfred, South Africa, stn No. PF 13812–3.

Additional material examined. 1 large male, 2 immature females, and 2 juveniles, SAM-A3859, Walker Point, near Knysna, South Africa, stn No. PF 10258. 1 male, Cape Point Lighthouse, South Africa, stn No. PF 15378, 5 September 1902, SAM A4402. 1 mature female & 1 immature female, SAM A4392. One male, Delagoa Bay, Mozambique, SAM-A10280.

Description. Based on male "a", body length 19.87 mm, SAM-A3859. Head and pereonites slender. Head smooth, not rounded dorsally; eye large, distinctive; head/pereonite 1 concave along dorsal margin; without anterodorsal projections; without anterodorsal projections, without weak anterolateral projection, without anteriorly pointed mid-dorsal and lateral projections, without mid-ventral projections. Antenna 1 slender; 0.8 x body length; peduncle article 2 longest; peduncular article 3 straight; flagellum subequal in length to peduncle, with 27 articles, proximal article composed of 3 articles. Antenna 2 slender; 0.4 x antenna 1 length; peduncle with several feeble setae; flagellum 0.4 x peduncular length, with 2 articles.

Labrum notched, forming shallow quadrilateral projections. Mandible right side incisor with 5 teeth; lacinia mobilis with 5 teeth; accessory setal row with 3 setae; left side incisor with 6 teeth; lacinia mobilis with 2 reverse-trapezoid plates, accessory setal row with 3 setae; palp article 2 with 7 lateral setae; palp article 3 setal formula 1-27-3-1. Labium finely setose on inner and outer lobes. Maxilla 1 outer plate with 7 stout apical setal-teeth; palp distal margin with 6 triangular projections, each with a slender or robust seta (8 robust setae and a row of slender setae). Maxilla 2 inner plate triangular with about 11 apical robust setae; outer plate elongate with about 17 apical setae. Maxilliped basal endite (inner plate) quadrilateral, with 1 small nodular seta, with 9 setae near distal margin; ischial endite (outer plate) oval, 3 x length of inner plate, inner margin minutely serrate, with a few fine setae, with 2 setae on inner margin, with 5 setae on outer margin; palp article 2 scarcely setose on inner margin; palp article 3 not expanded, with dense (17–20) distal setae; palp article 4 (dactylus) falcate.

Pereon. Head length 1.14 mm, pereonite 1, 1.7 mm, pereonite 2, 3.25 mm, pereonite 3, 3.71 mm, pereonite 4, 3.9 mm, pereonites 6, 1.41 mm, pereonite 7, 0.82 mm, pereonite 4 longest. Pereonite 2 with anterolateral triangular projection, with midlateral projection, without paired mid-dorsal projections, without paired midventral projections, without dorsodistal projection, without ventral projection between insertion of gnathopods, without acute sternal spine. Pereonite 3 with subacute anterolateral projection, without mid-dorsal projections, without paired midventral projections, without dorsodistal projection. Pereonite 4 without anterolateral projection; without mid-dorsal projections. Pereonite 5 without anterolateral projection, without dorsal projections. Pereonites 6 and 7 not articulated obliquely.

Gnathopod 1 propodus triangular, with 3 rows of submarginal setae on distal part (near anterior margin), palm begins 1/5 along posterior margin, smooth, with 1 robust seta near corner of palm, dactylus straight. Gnathopod 2 situated about 1/3 along posterior margin; coxa vestigial; basis subequal in length (slightly shorter) to pereonite 2, with small projection near distal margin; ischium without distolateral projection; carpus 0.18 x propodus length; propodus elongate (subrectangular), large, length 2.1 x width, anterodistal margin widely concave, without dorsodistal triangular projection, with one small mid-dorsal projection; palm proximal projection with 1 robust (grasping) seta, palm margin concave, smooth, with three triangular projections distally, with large midpalmar spine or with 2 distal spines, with deep narrow sinus and deep broad sinus, with broad well developed distal shelf, with several small projections.

Gill 3 length about 1/2 of corresponding pereonite, curved anteriorly. Pereopod 3 ovate; article 1 length about 5 x width, article 1 with 5 distal setae and 1 lateral seta; article 2 tiny, conical. Gill 4 length about 1/2 of corresponding pereonite, curved anteriorly. Pereopod 4 ovate; similar in length to pereopod 3; article 1 length about 5 x width, article 1 with 5 distal setae and 1 lateral seta; article 2 tiny, conical. Pereopods 6 and 7 present.

Pleon. Uropod 1 present; peduncle free, peduncle elongate, peduncle length about 2/3 width; ramus length 4– 5 x width, ramus 2 x peduncular length. Uropod 2 ramus vestigial.

Holotype male, body length 13.91 mm, SAM-A3859. Antenna 1 longer than the body length; peduncle article 2 longest followed by article 3. Head length 0.85 mm, pereonite 1, 0.65 mm, pereonite 2, 2.25 mm, pereonite 3, 2.91 mm, pereonite 4, 2.71 mm, pereonites 6, 2.86 mm, pereonite 7, 0.69 mm, pereonite 4 longest. Pereonites 3, 4 and 5 subequal and longest. Pereonite 2 with an anterior lateral projection and mid-lateral projection. Pereonite 3 with a anterior lateral projection. Pereonites 6 and 7 articulated nearly perpendicular. Gnathopod 2 basis longer than pereonite 2 length, with large triangular projection on distal margin and small one near basal end; ischium with small triangular projection distally; propodus with small dorsal projection about 2/5 from apical end. Pereopods 5 to 7 lacking in this specimen.

Habitat. Marine; littoral.

Distribution. Cape Province, South Africa: Cape Point; Walker Point near Knysna; Glendower Beacon near Port Alfred. Mozambique: Delagoa Bay.

Remarks. K.H. Barnard (1916) briefly described the new species Orthoprotella mayeri K.H. Barnard, 1916 collected from Glendower Beacon, near Port Alfred, South Africa, and considered Mayer’s (1903) Orthoprotella sp. collected from Sydney, Australia and Singapore as a junior synonym of Orthoprotella mayeri . He wrote that “I hope to give a figure of the hand of the adult male on a future occasion, as the specimens came to light only after the plates had been executed” ( K.H. Barnard 1916: 285) but he did not complete the description after that. The synonymy of Mayer’s (1903) Orthoprotella sp. as Orthoprotella mayeri was accepted by McCain and & Steinberg (1970) in their catalogue of world Caprellidea and Lowry & Stoddart (2003) in their catalogue of Australian Amphipoda . During our studies of the caprelloid amphipods of New South Wales, we had the opportunity to make a detailed comparison based on the type specimen of Orthoprotella mayeri (sensu lato) from South Africa and specimens of Orthoprotella mayeri (sensu lato) from New South Wales. We found significant differences between them, particularly features of the mandibular palp, pereonites 6 and 7 and the uropod on the urosome. This differentiation is discussed in the remarks of the following new species of Orthoprotella .

Five series of specimens of Orthoprotella mayeri collected from the coasts of southern South African and Mozambique were deposited with the South African Museum, Cape Town. Two series of specimens, i.e., SAM-A90 (1 male) and SAM-A3859 (1 large male, 2 immature females, and 2 juveniles) corresponded to specimens which K.H. Barnard (1916) described. Although, a male specimen, 13.91 mm in body length (SAM-A90), was assigned as holotype in the catalogue of SAM, the mouthpart and urosome of this specimen had already been dissected by somebody prior to our study. Unfortunately the slide of the dissected mouthparts of Orthoprotella mayeri was not deposited in SAM (van der Merwe, personal communication, 12 March 1996). Thus, we redescribed the large male from SAM-A3859 which is in the series of specimens used by K.H. Barnard in his original description of Orthoprotella mayeri . Paratypes were not assigned by K.H. Barnard. Since the mature males and females of this species have all also lost pereopods 5 to 7 during the collecting, sorting or preserving process, additional material will be required for completing the species diagnosis.

K.H. Barnard (1925) again described “ Orthoprotella mayeri ” based on the specimens collected from Cove Rock, Algoa Bay, Cape St. Fancis, Cape Seal and Cape point and S.S. “Pieter Faure”; these specimens were different collections from K.H. Barnard (1916), except for S.S. “Pieter Faure”. K.H. Barnard (1925: 373) described that the well-developed specimen possessed “a dorsal pair [of projections] inclined somewhat forward” on “ segment 2” and “a pair of dorsal tubercles” on “segment 3” and that body length of male are up to 20 mm. Segments 2 and 3 are thought to correspond to pereonites 2 and 3, respectively. Although the maximum body size of K.H. Barnard’s (1925) specimens is equal to the present description of male in body length of 19.87 mm based on the collection of K.H. Barnard (1916), the tubercles or projections on pereonites 2 and 3 were not recognized on the type specimens.

Griffiths (1973) recorded the occurrence of “ Orthoprotella mayeri ” from Inhaca Island, southern Mozambique with the short description that specimens over 10 mm bear a pair of dorsal tubercles on segment 3. Shortly after that publication ( Griffiths 1973), Griffiths (1976) figured O. mayeri in his "Guide to the benthic marine amphipods of Southern Africa" with a pair of distinct mid-dorsal and anterolateral projections on pereonite 2 and a pair of mid-dorsal projections on pereonite 3. The presence of dorsal projections on pereonites 2 and 3 of the “ O. mayeri ” of K.H. Barnard (1925) and Griffiths (1973, 1976) indicates the possibility that a different species belonging to Orthoprotella or a related genus also occurs along the coasts of South Africa and Mozambique.

Figures

FIGURE 1. Orthoprotella mayeri K. H. Barnard, 1916, male “ a ” from Walker Point, South Africa; a, lateral view; a’, antero-lateral projection on pereonite 2; a’ ’, antero-lateral projection on pereonite 3. Male, holotype from Glendower Beacon, South Africa; b, lateral view. Scale 1.0 mm.

FIGURE 2. Orthoprotella mayeri K. H. Barnard, 1916, male “ a ” from Walker Point, South Africa; a, flagellum of antenna 2; b, gnathopod I; c, gnathopod 2; d, pereopod 4, e, pereopod 5; f, urosome (lateral view); g, urosome (ventral view). Scale: a, b and d-g = 0.1 mm, c = 1.0 mm.

FIGURE 3. Orthoprotella mayeri K. H. Barnard, 1916, male “ a ” from Walker Point, South Africa; a; maxilliped; a’, inner plate of maxilliped; b, left mandible; b’, incisor, lacinia mobilis and finely setose of left mandible: c, right mandible; c’ incisor, lacinia mobilis and finely setose of left mandible; d, maxilla 1; e, maxilla 2; f, labrum; g, labium. Scale 0.10 mm.