Porcellana paivacarvalhoi Rodrigues da Costa, 1968

Ferreira, Luciane Augusto de Azevedo & Tavares, Marcos, 2019, On the identity of Porcellana paivacarvalhoi Rodrigues da Costa, 1968 (Crustacea: Anomura: Porcellanidae), Papéis Avulsos de Zoologia (Pap. Avulsos Zool., S. Paulo) 59, pp. 1-7 : 2-6

Porcellana paivacarvalhoi Rodrigues da Costa, 1968 ( Figs. 1 A-J; 2A-D)

Type material: male lectotype, cl 10.3, cw 9.6 ( MZUSP 40050), Brazil, São Paulo, São Sebastião, Praia de São Francisco, H. Rodrigues da Costa coll. Paralectotypes: 1 female, cl 10.0, cw 9.3 ( MZUSP 10621), 1 female cl 10.5, cw 10.6 ( MOUFPE 7734). Same data as lectotype.

Comparative material: Porcellana platycheles ( Pennant, 1777) ( Figs. 2E, F ; 3 A-J): France: 1 male, cl 4.4, cw 4.2, 5 females, cl 5.0 to 9.6, cw 4.5 to 8.8 ( MZUSP 18815 ), Îles Chausey, Granville, K. Baba et al. coll., 26-31.viii.1996, intertidal. 3 males, cl 10.4 to 11.8, cw 9.3 to 11.4 ( MZUSP 36347 ), Rothéneuf Le Pont, Saint-Malo , Bretagne, 29.xii.1993. 7 males, cl 5.2, cw 4.8 to cl 11.8, cw 11.0, 7 ovigerous females,cl 8.1,cw 7.7to cl 10.9,cw 10.0( MZUSP 16261 ), Roscoff , Bretagne, J.-M. Amouroux coll., vi.2004. 2 males, cl 10.6, cw 9.8 and cl 10.8, cw 10.1 ( MZUSP 6807 ), Quiberon , Bretagne, M. Türkay coll., 02.ix.1981. 2 males, cl 4.4, cw 3.9 and cl 5.7, cw 5.1, 1 female, cl 4.6, cw 4.5 ( MZUSP 16408 ), Biarritz, J.-M. Amouroux coll., 20.ii.2004. Portugal: 1 male, cl 8.2, cw 7.8 ( MZUSP 36759 ), Praia da PoÇa , São João do Estoril , Estoril , Lisboa, 38°42 ′ 04 ″ N- 09°23 ′ 26 ″ W, L. R. L. Simone coll., 13.vii.2014. 3 males, cl 9.7 to 10.9, cw 8.8 to 10.0 ( MZUSP 11107 ), locality unknown .

Pisidia brasiliensis Haig in Rodrigues da Costa, 1968: 1 ovigerous female, cl 4.4, cw 4.7 ( MHNCI 3840), Brazil, Santa Catarina, Penha, ArmaÇão de Itapocoroy, P.P.B. Macedo coll., 20.vi.2011, associated with Nodipecten nodosus ; 1 male, cl 3.6, cw 3.7, 2 ovigerous females, cl 4.1, cw 4.3 and cl 4.8, cw 5.0 ( MHNCI 3684), same locality, P.P.B. Macedo coll., associated with Nodipecten nodosus ; 2 ovigerous females,cl 3.7, cw 3.9 and cl 4.0,cw 4.2 ( MHNCI 3130), same locality, P.P.B. Macedo coll., 14.vii.2010, associated with Nodipecten nodosus . The above specimens were reported by Macedo et al. (2012) as P.platycheles .

Type locality: Brazil, São Paulo, São Sebastião, Praia de São Francisco.

Redescription of the lectotype: Carapace subcircular, longer than broad in males and females, slightly rugose dorsally, pubescent. Front-orbital region depressed, smooth. Frontal width approximately ⅓ maximum carapace width. Frontal margin serrate, fringed with short setae; trilobate in dorsal and frontal views; median lobe rounded, overreaching lateral lobes; lateral lobes round- ed. Outer orbital angle well defined, rounded, with spinulate margin. Carapace anterolateral margin spinulate. Carapace lateral margin well-defined by row of conspicuous spines. Epibranchial region slightly swollen. Epibranchial angle well-defined by distinct notch; cervical groove well-defined. Carapace posterolateral surface plicate; posterior margin concave. Branchiostegite entire (without membranous areas), with longitudinal, subparallel, pilose wrinkles; superoanterior region spinulate. Branchiostegal margin fringed with long, plumose setae.

Ocular peduncle short, smooth. Orbit with smooth margin, fringed with short setae. Cornea large, dilated.

Antennular basal segment large, 2 anteromesial spines,1 anterolateral spine. Segments 2 and 3 unarmed, subcylindrical; segment 3 as long as segment 2, slightly broadened distally.

Antennal segments covered with short setae. Coxa subtriangular, with granulate margins. Basis-ischium approximately ⅔ length of merus, spinulate mesially; distal tubercle on mesial surface. Merus granulate mesially. Carpus approximately half of total length of merus. Flagellum long; short articles with inconspicuous setae.

Mxp 3 dorsal surface smooth, covered with short setae.Exopod slender,lanceolate,reaching half total length of merus, fringed with long, plumose setae; flagellum well developed. Ischium lateral lobe long, separated by V-shaped incision. Merus as long as ischium; mesial lobe broad, rounded, with small spine mesially.

Thoracic sternite 3 median lobe broad anteriorly, rounded, fringed with short, setae; lateral lobes narrow, subtriangular, slightly shorter than median lobe. Sternites 4-7 broad, sutures between sternites incomplete, distinct only laterally. Sternite 8 anterior margin convex, posterior margin concave.

P1 slightly unequal, robust, flattened, covered with dense, short setae dorsally; propodus and dactylus with sparse granules, more evident next to pollex; smooth ventrally, devoid of setae. Merus approximately ¼ length of carpus; mesial lobe well-developed, rounded, spinulate; distal spine ventrally. Carpus approximately half length of propodus, with subtriangular, spinulate lobe on proximal third mesially; distal spine laterally, lateral margin with row of spines. Propodus broad, lateral margin with row of spines;fringed with long,dense,plumose setae laterally. Fixed finger approximately ⅓ total length of propodus; not overreaching dactylus. Dactylus longer than fixed finger. Fingers tip curved; cutting edges of fingers with conspicuous granules, with traces of short setae.

Walking legs decreasing in size from P2 to P4, slender, covered with long, dense,plumose setae. P2-P4 carpi approximately ⅔ length of meri. P2-P4 carpi approximately ⅔ length of propodi. P2-P4 propodi with 3 movable, corneous spines ventrally, 1 on distal third, 2 on distal corner near articulation with dactylus; P2-P4 dactyli approximately half length of propodi; longitudinal row of 5 spines ventrally.

Abdomen subrectangular in males and females, somites smooth dorsally, lateral margins with long, plumose setae. Male gonopods well-developed on somite 2; female pleopods well-developed on somites 3-5. Uropods slender, reaching distal margin of telson.Telson smooth dorsally, broader than long, subdivided into 7 plates.

Remarks: Porcellana paivacarvalhoi was established based on 4 males and 3 females from southeastern Brazil (São Francisco beach, São Sebastião, São Paulo), one male and one female of which remain in the collections of the MZUSP and one additional female was retrieved from MOUFPE.The syntypes were originally in Rodrigues’ da Costa collection and,after his death, the remains of his original collections were donated to MZUSP. The female housed at the MOUFPE was a donation from MZUSP.The male syntype is better preserved than either of the females and therefore is herein chosen as the lectotype (MZUSP 40050, Figs. 1 A-J; 2A-D). The females (MZUSP 10621; MOUFPE 7734) are the paralectotypes. The designation of the lectotype and its redescription and illustration are made in an effort to clarify the identity of the species and promote nomenclatural stability.

Rodrigues da Costa (1968) stated that P. paivacarvalhoi was similar to the eastern Atlantic P. platycheles and, more particularly, to the west African P. platycheles africana Chace, 1956 . Veloso & Melo (1993) placed P. paivacarvalhoi in synonymy with P. platycheles based on the examination of one“male paratype ” [sic] (MZUSP 8951). That specimen no longer exists in the MZUSP collections, however there is no evidence that it was indeed a syntype, and it is unclear from their publication whether Veloso & Melo ever compared the purported syntype of P. paivacarvalhoi with specimens of P. platycheles . Furthermore, they never addressed the morphological similarities between P. paivacarvalhoi and P. africana , whose specific status has recently been confirmed by Griffiths et al. (2018) (see also d’Udekem d’Acoz, 1999). Despite this, the synonymy between P. paivacarvalhoi and P. platycheles has been implicitly accepted without further analysis ( Melo, 1999; Rodríguez et al., 2005; Osawa & McLaughlin, 2010; Griffiths et al., 2018).

Porcellana paivacarvalhoi resembles P.africana in having the lateral margin of the P1 carpus armed with one conspicuous terminal spine, but can be distinguished from it in that the lateral margin of the P1 carpus is armed with 1, 2 or more spines of different sizes ( Figs. 1G ; 2C, D ). Conversely, the lateral margin of the P1 carpus has no spines other than the distal one in P. africana ( Chace, 1956; Griffiths et al., 2018). Porcellana africana further differs in being overall less spinose and more tuberculate and rugose beneath the pubescence covering the carapace, whereas the carapace is nearly smooth dorsally in P. paivacarvalhoi ( Figs. 1A ; 2A ). Porcellana paivacarvalhoi is not, therefore, a synonym of P.africana .

In P.paivacarvalhoi , as in P.platycheles , the carapace is nearly smooth dorsally, whilst its anterolateral and lateral margins have conspicuous spinules ( Figs. 1A, C ; 2A ; 3A ); the carapace and P1 dorsal surfaces are provided with either short or long setae; the antennular basal segment with 1 or 2 anterolateral spines ( Figs. 1D ; 3D ); the lateral margin of the P1 carpus is armed with 1, 2 or more spines of different sizes ( Figs. 1G ; 3G ); the P1 carpus mesial lobe is either well developed ( Figs. 1G ; 3G ) or inconspicuous; and the P2-P4 dactyli have a longitudinal row of 5 or 4 spines ventrally ( Figs. 1H ; 3H , respectively). In addition to the P1 lateral spines, P. paivacarvalhoi further resembles P.platycheles in having conspicuous spinules on both the anterolateral and lateral margins of the carapace, and a nearly smooth carapace and P1. In these and other respects P. paivacarvalhoi lacks sufficient morphological differences to be recognized as a separate species from P. platycheles and, therefore, is confirmed herein to be its junior synonym.

The native range of Porcellana platycheles is in the eastern Atlantic (from Ireland southward to the Canary Islands) and in the Mediterranean Sea, from the intertidal zone down to 5 m ( d’Udekem d’Acoz 1999). Its presence in São Sebastião in southeastern Brazil in the late 1960s most probably represents an historical case of human-mediated introduction by shipping activities. Indeed, São Sebastião, which started operation in 1963, is a busy city port catering to ocean-going vessels. The repeated presence of eastern Atlantic/Mediterranean species in southeastern Brazil ( Tavares, 2011; Tavares & MendonÇa, 2004; Tavares & Rössener, 2019; this report), indicates human-mediated connectivity between eastern Atlantic source areas and Brazilian points of entry and is a reflection of the level of inoculation pressure in the 1960s.

Porcellana platycheles did not manage to establish itself in São Sebastião, nor has it been recorded subsequently from elsewhere in Brazil. Macedo et al. (2012) reported on 1 male and 5 females (MHNCI 3840, 3684, 3130) purportedly belonging to P. platycheles associat- ed with mussel farming in Santa Catarina, south Brazil. However, upon examination all these specimens proved to be Pisidia brasiliensis Haig in Rodrigues da Costa, 1968.

Figures

Figure 1. (A-J) Porcellana paivacarvalhoi Rodrigues da Costa,1968, male lectotype,cl 10.3 mm,cw 9.6 mm (MZUSP 40050). (A) Carapace,dorsal view.(B) Frontalorbital region of carapace,frontal view.(C) Carapace,lateral view,emphasizing branchiostegite.(D) Left basal segmentof antennule,ventral view.Thearrow points to the anterolateral spine. (E) Left antenna, lateral view (flagellum omitted). (F) Left Mxp 3, ventral view (flagellum of exopod omitted). (G) Left major P1, dorsal view.Theblack and greyarrows point to thecarpal lateral spines and mesiallobe,respectively.(H) RightP4,lateral view.(I)Telson,dorsal view.(J)Thoracic sternum, ventral view.Setae omitted.Scale bars:1 mm.

Figure 2. (A-D) Porcellana paivacarvalhoi Rodrigues da Costa, 1968, male lectotype, cl 10.3 mm, cw 9.6 mm (MZUSP 40050). (A) Cephalothorax, dorsal view. (B) Cephalothorax, ventral view. (C) Major and minor P1, dorsal views. (D) Minor and major P1, ventral views. (E, F) Porcellana platycheles (Pennant,1777), male, cl 8.2 mm,cw 7.8 mm (MZUSP 36759),habitus, dorsal and ventral views,respectively.Color in ethanol.Scale bars:3 mm.

Figure 3. Porcellana platycheles (Pennant, 1777), male, cl 8.2 mm, cw 7.8 mm (MZUSP 36759). (A) Carapace, dorsal view. (B) Frontal-orbital region of carapace, frontal view.(C) Carapace,lateral view,emphasizingbranchiostegite.(D) Left antennule,ventral view.Thearrow points tothe anterolateral spines.(E) Left antenna, ventral view.(F) Left Mxp3, ventral view (flagellum of exopod omitted).(G) Right major P1, dorsal view.The black and grey arrows point to the carpal lateral spine and mesial lobe,respectively.(H) Right P4, lateral view.(I)Telson,dorsal view.(J)Thoracic sternum,ventral view.Setae omitted.Scale bars:1 mm.