Paradeutella multispinosa Schellenberg, 1928 Pseudoprotella phasma ( Montagu, 1804 )

Zeina, Amr F. & Guerra, José M., 2016, Caprellidae (Crustacea: Peracarida: Amphipoda) from the Red Sea and Suez Canal, with the redescription of Metaprotella africana and Paradeutella multispinosa, Zootaxa 4098 (2), pp. 227-253 : 242-249

Paradeutella multispinosa Schellenberg, 1928

( Figs. 8–12 )

Paradeutella multispinosa Schellenberg, 1928: 676 –677, fig. 209.

Material examined. Male “a”, female “b”, 2 males (one of them lacking head), 1 female (ZMB 21555) collected during the Cambridge Suez Canal Expedition; 2 males and 1 female (ZMB 17533) collected from Suez by E. Bannwarth in 1914 (see remarks for discussion about the type material)

Description. Male “a” (ZMB 21555)

Body length 5.4 mm. Head with a dorsal acute projection; suture between head and pereonite 1 non -marked. Pereonite 1 with a dorsal acute projection. Pereonite 2, 3 and 4 with two dorsal acute projections forwardly and another dorsal acute projection backwardly. Pereonite 2, with a lateral projection proximally and other projection near the coxa, both of them forwardly. Pereonite 3 with a lateral proximal projection and other projection near the gill insertion. Pereonite 4 with a small rounded projection proximally and other projection near the gill insertion. Pereonite 5 with a proximal lateral projection and two dorsal projections. Pereonite 6with a dorsal small projection. Pereonite 7 with a small projection near the coxa of pereopod 7. Eyes distinct, small. Gills on pereonites 3 and 4, oval, length 2 times width.

Mouthparts. Upper lip symmetrically bilobed, without setulae. Lower lip broken. Mandibles with no sign of mandibular molar; left mandible with incisor 5-toothed, lacinia mobilis 5-toothed followed by three plates; right mandible with incisor 5-toothed, lacinia mobilis transformed into a plate, followed by other plate; molar flake absent; palp three -articulate, second article with a single seta, third article with a distal robust setae (like a knob) and a setal row formula 1-x -1, being x= 7 in left mandible and x= 8 in right mandible. Maxilla 1 outer lobe carrying 6 robust seta; distal article of the palp with 4 setae. Maxilla 2 inner lobe triangular, with 4 setae; outer lobe rectangular, about 1.5 times as long as inner lobe, with 4 setae. Maxilliped inner plate small and rounded with 2 setae; outer plate elongate, 3 times as long as the inner plate, with 5 setae; palp 4-articulate, dactylus curved (falcate) with row of setulae.

Antenna 1 about 3⁄4 of body length; flagellum 10-articulate. Antenna 2, about 0.4 x antenna 1 length, without swimming setae, flagellum two -articulate, peduncular article 1 with a distal projection.

Gnathopod 1 basis as long as the combination of ischium, merus and carpus; palm of propodus non -serrate, provided with two grasping spines; dactylus margin smooth. Gnathopod 2 inserted on the anterior half of pereonite 2; basis 1.3 times as long as pereonite 2, with a projection distally; ischium rectangular with a lateral acute projection; merus rounded; carpus triangular; propodus oval with a hump dorso laterally, more marked in some specimens (see Fig. 12 ), length about 1.6 times of width, provided with small grasping spine proximally and an acute projection medially and a hump distally; dactylus smooth

Pereopods 3 and 4 minuscule (smaller than 0.1 mm), 1-articulate, elongate, provided with two distal setae. Pereopods 5, 6 and 7 lacking (missing also in all the specimens examined)

Penes large, length about 2 times width.

Abdomen without clear appendages, with a pair of lateral lobes well marked and setose, and a single dorsal lobe provided with a pair of plumose setae.

Female “b” (ZMB 21555)

Similar to holotype male apart from the following characters: flagellum of antenna 1 with 8 articles; gnathopod 2 without projections on basis and ischium, propodus lacking hump and the medial projection smaller than in male; oostegites on pereonite 3 very setose, on pereonite 4 scarcely setose; abdomen without well marked setose lobes.

Remarks. Schellenberg (1928) in the original description of P. multispinosa reported the following material: 1 young specimen 3 mm from Km76 (Ferry Port); several males 3.5–5.5 mm and young specimens, 3 female with brood -sac 3.5–4 mm from K. 0 (Kabret); 1 female with brood -sac 3.5 mm from K. 13 (Little Bitter Lake); 1 male 5 mm Km. 157 (El Shatt).

McCain & Steinberg (1970) pointed out that the type material was deposited at the Museum für Naturkunde, Berlin. All the material of this species deposited at the Museum has been examined. The museum houses two lots of specimens (ZMB 17533 and ZMB 21555) of P. mutispinosa . ZMB 17533 contain material (2 males and 1 female, see Fig. 12 lower ) collected by E. Bannwarth (21 February 1914). This material was collected from Suez and in the database of the Museum is considered as unspec. Typus. The other lot (ZMB 21555) comprises 3 males (1 of them very damaged, lacking head) and 2 females and, according to the label and database, it was collected during the Cambridge Expedition to the Suez Canal (1924). Schellenberg (1928) describes this species as part of the report on the Amphipoda collected during Cambridge Expedition to the Suez Canal but he only figured the lateral view and ganthopod 2 of one adult male (Schellenberg, 1928, fig. 209). Therefore, this material collected in 1924 (ZMB 21555) might be part of the material in which the description of the species is based on, and could correspond with the type material. However, it seems that Schellenberg (1928) reported more material in his description than that included in the lot ZMB 21555, which contain only 5 specimens. The other lot (ZMB 17533), collected previously to the Cambridge Expedition, was probably later identified as P. multispinosa . Therefore, it seems more adequate to consider as type material the lot ZMB 21555. However, at the Museum records, the lot ZMB 17533 is registered as type material and we cannot discard the possibility that Schellenberg used this material collected before to describe the species. For all these reasons, we have decided not to designate a lectotype so far, but we based the descriptions on a male “a” and female “b” from the lot ZMB 21555. Anyway, the material of both lots clearly belongs to the same species and all the specimens of both lots (except for the damaged male without head) have been figured (male “a” and female “b” in Fig. 8 , and the rest of specimens in Fig. 12 ).

Schellenberg (1928) considered that the rudiments of the abdominal appendages of P. multispinosa showed the same arrangement of setae that Mayer figures for the genus (Mayer, 1890, plate 5, figure 34). He also indicated that the mouthparts are like those shown by Mayer for the genus, but in Mayer descriptions, mouthparts of this genus are not clear.

Paradeutella was established by Mayer (1890). McCain & Steinberg (1970) selected Paradeutella bidentata Mayer, 1890 as the type species of the genus. At the moment, 9 species have been described for the genus Paradeutella : P. armata Mayer, 1903 ; P. bidentata Mayer, 1890 ; P. bituberculata Barnard, 1937 ; P. echinata (Haswell, 1880); P. laevis Mayer, 1903; P. multispinosa Schellenberg, 1928 ; P. serrata Mayer, 1903 , P. spinosa Mayer, 1903 and P. tanzaniensis Guerra-Garcia, 2001 . Most of these species are “species inquerendae” so the genus needs a full revision and all the species should be redescribed. The diagnosis of this genus is, therefore, not clear, as shown by Takeuchi (1993: table 2). The presence⁄absence of molar and the structure of the abdomen are not clear. Mayer considered two pair of abdominal appendages in males and one pair in females (see Mayer 1890: 8) but this is not clear in the figures of the species for which the abdomen is figured, such as P. serrata , which seems to lack these appendages (or lobes -like appendages). Mayer (1890: plate 5, fig. 34) also figured the abdomen of P. bidentata , the type species of the genus, and the appendages are not clear since they looks more like lobes. Mouthparts are not described for the type species, so it is not clear if there is molar or not.

The description of P. multispinosa reveal s that the mandibles lack molar, and the abdomen lacks clear appendages (only marked lobes are present). In fact the maxilliped and other characteristics, such as the tiny pereopods 3 and 4, the mandibular palp with setal formula 1-x -1 with additional distal knob, maxilliped with small inner plate and dacylus falcate, totally agree with those in the genus Pseudaeginella (see e.g Lacerda et al., 2011). This indicates that probably the genus Paradeutella should be synonymised with Pseudaeginella . To see if the diagnostic characters of P. multispinosa correspond with those of the genus Paradeutella , we have examined the type material of P. bidentata , the type species of the genus, which includes 8 specimens: 1 male (ZMUC -CRU - 4758); 1 male, 3 females, 1 premature females and 2 juveniles ZMUC -CRU -5822), all of them collected from Sri Lanka (Ceylon). A careful examination of the specimens revealed that the tiny pereopods 3 and 4 are present, the mouthparts are similar to those in P. multispinosa : inner lobe of maxilliped very reduced, dactylus of the maxilliped palp falcate; mandibles without molar (or extremely reduced to a vestigial tip), mandibles palp with setal formula of 1-x -1 and short distal knob, as in P. multispinosa ( Fig. 9 present study), and in Pseudaeginella species (see e.g. Fig. 3 C,B in Lacerda et al., 2011); abdomen lacking developed appendages. Consequently, we can assess that diagnostic characters of the genus Paradeutella include the lack of molar in the mandibles, and lack of clear appendages in the abdomen. According to these observations, the genus Paradeutella could be considered as synonymous of Pseudaeginella . Both genera were described in the same year (Mayer, 1890). Several species of Pseudaeginella have been recently described and most of them include detailed taxonomic descriptions according to the modern taxonomy, so, in our opinion, it would be advisable to maintain Pseudaeginella as valid genus and Paradeutella (with most of the species needing a redescription) as synonymous. However, a complete redescription of type material of Paradeutella bidentata , together with redescriptions of the majority of species of Paradeutella , which are based on very poor and incomplete descriptions, are still necessary before undertaken this synonymy to clarify the status of these Paradeutella species.

Guerra-Garcia (2001) included tentatively P. tanzaniensis inside the genus Paradeutella , although pointed out that the abdomen of P. tanzaniensis (provided with two developed appendages) was different from the abdomen of the genus (figured and described by Mayer, 1903). P. tanzaniensis has also molar so, according to the examination of P. bidentata , P. tanzaniensis should be probably transferred to other genus such as Deutella , or even Protella , but not Paradeutella . Similarly, Laubitz (1991) in a study of the Caprellids from the western Pacific (New Caledonia, Indonesia and the Philippines) included figures of Paradeutella laevis and P. spinosa (not collected from the type locality). In both cases, the abdomen lack clear appendages or lobe-like appendages so this agrees with Paradeutella / Pseudaeginella material, but there is a clear molar, and the pereopods 3 and 4 are more developed, so, at least for Paradeutella spinosa , the material examined of Laubitz (1991) do not belong to the genus Paradeutella / Pseudaeginella . Consequently, it should be transferred to other different genus, since P. bidentata , the type species of the genus, indicate absence of molar as diagnostic character of the genus. Furthermore, the ganthopod 2 figured for Mayer (1903) for P. laevis and P. spinosa , is totally different to the gnathopod figured by Laubitz (1991). In the case of specimens of Paradeutella laevis of Laubitz (1991), they could belong to the genus Paradeutella / Pseudaeginella (mandible is not figured by Laubitz so the molar could also be absent) but in the case of P. spinosa of Laubitz, this should be, without doubt, transferred to other genus, probably Deutella , based on the presence of molar.

Material of Mayer (1912) and Guerra-Garcia (2004) collected from Australia and described as Paradeutella sp. should be also reviewed according to the diagnosis of the genus, to confirm if they belong to Paradeutella / Pseudaeginella or not.

In summary, a whole revision of the genus Paradeutella , including redescription of the type material of P. bidentatata and complete redescriptions based on type series or newly collected material from the type localities of P. armata , P. bituberculata , P. echinata , P. laevis , P. serrata and P. spinosa Mayer , is necessary to confirm is this genus should be synonymised with Pseudaeginella , as suggested in the present study,.

Distribution. Type locality: Suez Canal (Kabret, Little Bitter Lake, El Shatt, and the Ferry Port). Only reported so far from the type locality [?] Pseudoprotella phasma ( Montagu, 1804)

Figures

FIGURE 3. Lateral view figures of a male and female of Hemiaegina minuta.

FIGURE 8. Lateral view figures of male “ a ” and female “ b ” (ZMB 21555) of Paradeutella multispinosa

FIGURE 9. Mouthparts of male “ a ” of Paradeutella multispinosa.

FIGURE 10. Antenna 1, 2, gnathopod 1, 2 of male “ a ” and gnathopod 2 of female “ b ” of Paradeutella multispinosa.

FIGURE 11. Pereopods 3, 4 and abdomen of male “ a ” and abdomen of female “ b ” of Paradeutella multispinosa.

FIGURE 12. Lateral view figures of specimens of Paradeutella multispinosa. Male and female (collected during the Cambridge Suez Canal Expedition together with the male “ a ” and female “ b ”) (ZMB 21555) (upper); two males and one female, collected in 1914 (ZMB 17533) (lower).