Austinixa aidae ( Righi, 1967 )

Almeida, Alexandre O., Araújo-Silva, Catarina L., Lucatelli, Debora, Bezerra, Luis Ernesto A., Balbino, Felipe C., Tamburus, Ana F. & Mantelatto, Fernando L., 2023, Austinixa bragantina Coelho, 2005: a junior synonym of A. aidae (Righi, 1967) (Brachyura: Pinnotheridae) supported by integrative morphological and molecular data, Zootaxa 5227 (2), pp. 229-250 : 234-238

Austinixa aidae ( Righi, 1967)

( Figs. 1–8 )

Pinnixa aidae Righi 1967: 107 , figs. 21–26; Coelho & Ramos 1972: 196; Schmitt et al. 1973: 101; Manning & Felder 1989: 4, fig. 2; Melo 1996: 429, 1 unnumbered fig.; Coelho 1997: 168; Calado et al. 1998: 112; Melo 1998: 495; Melo et al. 2003: 432.

Austinixa aidae .— Heard & Manning 1997: 393; Boschi 2000: 69; Coelho et al. 2002: 446; Coelho et al. 2004: 89; Dall’Occo et al. 2004: 459; Harrison 2004: 744; Harrison & Hanley 2005: 3650, fig. 1; Bezerra et al. 2006: 1043; Coelho et al. 2008: 43 ; Ng et al. 2008: 247; Palacios-Theil et al. 2009: 460, table 1; Almeida et al. 2010: 356, fig. 6; Mantelatto & Cuesta 2010: 343, figs. 1, 2 (description of zoea 1); Peiró & Mantelatto 2011: 5; Peiró et al. 2011: 262; 2013: 716; 2014: 84; Palacios Theil & Felder 2020: 104.

Austinixa bragantina Coelho 2005: 552 , figs. 1–17; Bezerra et al. 2006: 1039, fig. 1; Coelho et al. 2008: 43 ; Ng et al. 2008: 247; Lima 2009: 143, figs. 1–63 (description of larval development).

Pinnixa cristata .— Coelho 1969 (page not numbered); Coelho & Ramos 1972: 196; Coelho et al. 1980: 39; Barreto et al. 1993: 651; Melo 1996: 431, 1 fig. (not numbered); Melo 1998: 495; Barros & Pimentel 2001: 31 [not Austinixa cristata ( Rathbun, 1900) , see Coelho 1997].

Austinixa hardyi .— Heard & Manning 1997: 395, figs. 2–4; Harrison 2004: 744; Harrison & Hanley 2005: 3650, fig. 1; PalaciosTheil et al. 2009: 468; Palacios Theil & Felder 2020: 101.

Material examined. Pará: 1m (holotype of A. bragantina ; dissected chelae, third maxillipeds, and left pereiopods; preserved in glycerin), 25.iv.2004, Bragança , Ilha Canela (00°47′06″S 46°43′41″W), MOUFPE 13410 ; 5m, 5f (paratypes of A. bragantina ; preserved in glycerin, one female dissected, chelae, third maxillipeds, left pereiopods), 05.vi.2004, Bragança , Ilha Canela (00°47′06″S 46°43′41″W), MOUFPE 13411 ; 3m, 4f (topotypes of A. bragantina , preserved in 70% ethanol), i.2003, Bragança , Ilha Canela (00°47′06″S 46°43′41″W), MOUFPE 13411 ; 4m, 2f (topotypes of A. bragantina , preserved in 70% ethanol), 06.xi.2006, Bragança , Ilha Canela (0047′06″S 46°43′41″W), CCDB 4542 (genetic voucher) ; 1m, 1f (preserved in 70% ethanol), 13.vii.2003, Bragança , Ilha Canela, CCDB 4541 ; 1m, 1f, 13.vii.2003, Bragança , Ilha Canela, CCDB 4543 as Austinixa hardyi . Ceará: 1m, 07.v.1995, Fortaleza , Praia do Futuro (03°42′S 38°27′W), LABOMAR 703; 1f, 12.vi.1995, Fortaleza, Praia do Futuro (03°42′S 38°27′W), LABOMAR 704; 1m, 1f, 16.ii.2013, Fortaleza , Praia do Futuro (03°42′S 38°27′W), CCDB 4501 . Rio Grande do Norte : 1m, 12.i.1989, Natal , Alaga Mar, MOUFPE 3469 . Paraíba: 7m, 01.vi.1996, Pitimbu , Praia de Acaú, MOUFPE 9324 ; 7m, 19.iii.1996, Pitimbu , Praia de Acaú, MOUFPE 9329 . Pernambuco: 3m, 4f, 04.xii.1991, Itamaracá , Praia do Forno da Cal, MOUFPE 3476 ; 2m, 3f, 26.iv.1994, Itamaracá , Forte Orange, MOUFPE 3466 ; 3m, 6f, 27.viii.1991, Paulista , MOUFPE 3459 ; 3m (1 damaged), 2f, 1ni (damaged), iv.1993, Paulista , Praia do Janga, MOUFPE 3460 ; Paulista, Praia do Janga : 4m, 5f, 24.xi.1992, MOUFPE 3461 ; 2m, 2f, 26.x.1992, MOUFPE 3462 ; 4m, 4f, 17.08.1993, MOUFPE 3463 ; 3m, 5f, vii.1993, MOUFPE 3465 ; 2f, ix.1992, MOUFPE 3467 ; 3m, 3f, iv.1993, MOUFPE 3468 ; 1f, 27.viii.1993, MOUFPE 3474 ; 1m, 2f, 11.xii.1992, MOUFPE 3475 ; 1f, 05.xi.1987, Recife , Praia de Boa Viagem, MOUFPE 3470 ; Jaboatão dos Guararapes, Praia de Piedade : 7m, 9f, 12.iv.2008, UESC 1194 ; 4f, 12.vi.2008, CCDB 3095 ; 1m, 1f, 12.ii.1990, MOUFPE 3455 ; 1f, 08.xii.1988, MOUFPE 3478 ; 1f, 26.i.1990, Jaboatão dos Guararapes, Praia de Candeias , MOUFPE 3456 ; 1m, 1f, 08.iii.1989, Jaboatão dos Guararapes, Hospital da Aeronáutica , MOUFPE 3457 ; Jaboatão dos Guararapes, Venda Grande: 2f, 13.ii.1990, MOUFPE 3458 ; 1f, 08.iv.1989, MOUFPE 6245 ; 6m, 4f, 19.iv.2008, Cabo de Santo Agostinho , Praia do Paiva, UESC 1195 ; 2f, 20.vi.2015, Ipojuca , Praia de Serrambi, CCDB 5862 ; 1m, 05.ii.1989, Tamandaré , MOUFPE 3454 . Alagoas: 1f, 23.vii.2015, Japaratinga , Praia de Bitingui, CCDB 5861 ; 3m, 2f, 21.i.2020, São Miguel dos Milagres, Porto da Rua , CCDB 6555 . Bahia—: 1m, 1f, 31.iii.2009, Uruçuca , Praia do Pé da Serra, CCDB 3093 ; 1m, 1f, 07.ix.2004, Ilhéus , Praia dos Milionários, UESC 416 ; 4m, 7f, 06.v.2008, Canavieiras , Praia de Atalaia, sul da Ilha de Atalaia, UESC 1235 ; 6m, 6f, 2juv, 07.v.2008, Canavieiras , Praia de Atalaia, norte da Ilha de Atalaia, UESC 1236 ; 1m, 2f, 09.iii.2008, Belmonte , Praia de Mojiquiçaba, UESC 1192 ; Prado, Praia de Cumuruxatiba : 9m, 14f, 23.xi.2007, UESC 1124 ; 2m, 2f, 23.xi.2007, CCDB 3094 . Espírito Santo: 1f, 19.vi.2012, Anchieta , Praia de Iriri, CCDB 4071 ; 1f, 19.vi.2012, Praia de Piúma , CCDB 4073 . São Paulo: Ubatuba, Praia de Perequê-Açu : 3m, 2f, 17.vii.2004, UESC 1193 ;> 70 spec. 13.vii.2006, CCDB 2102 ; 5m, 6f, 13.iii.2005, CCDB 2194 ; 2m, 1f, 29.xi.2005, CCDB 2187 ; 1m, 2f, 16.ix.2008, CCDB 6876 ; 8m, 13f, 16.ix.2008, CCDB 6877 ; 13m, 13f (topotype of A. aidae , preserved in ethanol 70%, dissected—gonopod, antenna, chelae, third maxillipeds, pereiopods 2–5), 01.v.2009, Foz do Rio Juqueriquerê , Caraguatatuba (23°42′29″S 45°25′34″W, type locality), CCDB 3100 (genetic voucher) ; 1m, 3f, 24.vii.209, São Sebastião , Araçá, CCDB 4697 ; São Sebastião, Praia Baraqueçaba: 1f, 09.xi.2004, CCDB 2191 ; 1m, 3f, 09.xi.2007, CCDB 6398 ; 1m, 02.xii.2014, CCDB 5624 ; 4m, 02.xii.2014, CCDB 6010 ; 1m, 22.x.2011, Guarujá , Praia de Guaiuba, CCDB 6840 .

Diagnosis. Male carapace with two patches of setae anterior to cardiac ridge not in contact with lateral setae; male, apart from posterior patches, and female carapace with setae restricted to lateral and anterolateral margins, not extending onto lateral and anterolateral regions. Branchial ridges usually absent in adult specimens, when present never reaching orbit. Gape between fixed finger and dactylus of the chelipeds with dense tuft of setae; fixed finger long in males and females. G1 tip strongly curved, with triangular structure on the median portion.

Redescription based on topotype material (CCDB 3100).Carapace 1.9–2.7 times as wide as long; transversally oblong; narrowing near lateral margins; carapace regions poorly defined, with no grooves demarcating regions; dorsal surface smooth. Hepatic region slightly depressed; branchial ridges usually absent, but present in some specimens on one or both sides of carapace, being either inconspicuous for most of its length or conspicuous throughout all of its extension; shallow gastro-cardiac groove with slight depression on each side, each depression with dense tuft of setae in males, tufts usually separated, sometimes fused on median portion; smooth transverse ridge extending across entire cardiac region; carapace descending abruptly posterior to cardiac ridge; posterior margin straight or slightly convex; lateral margins with plumose setae ( Figs. 1–5 ). Anterolateral margins of carapace varying from convex to almost straight to slightly concave with plumose setae throughout their extension; posterolateral margins concave ( Figs. 1–4 ). Front not protruding, truncate, with two lobes separated by shallow median groove; lateral and anterior margins of lobes concave; anterolateral and median portions of front projecting slightly outwards. Orbits small, wider than half of width of front, fairly larger than eyes; very short ridge projecting obliquely from side of each orbit. Antennules shorter and wider than antennae. Antennae about as long as front and half of an orbit, with nine articles, third the longest ( Figs. 1–2 ).

Third maxilliped relatively large; merus pentagonal, outer margin mostly straight and distally rounded, inner margin with obtuse angle proximally and straight distally; propodus subrectangular, distal margin rounded possessing many long setae. Dactylus long, reaching distal third of merus, articulating near base of propodus; proximal portion slim, thickening towards distal portion; distal portion of dactylus rounded, with many long setae. First article of exopodite of third maxilliped with short spine near median portion ( Fig. 2 ).

Chelipeds strong, larger in males ( Fig. 1 ); continuous carina on dorsal surface of propodus; palm almost rectangular, with superior margin entirely convex and inferior margin convex near proximal end and concave near fixed finger; row of setae present on lower portion of inner face of palm, starting near proximal end and extending to fingers, deflected upwards ( Figs. 1 , 2 , 6 ). Large tuft of setae in gape between fingers, usually larger and denser in males ( Figs. 1 , 2 , 6 ).

Fixed finger relatively long, slightly deflected downwards; small blunt tooth near proximal end present in most male specimens followed by small serrated tooth near distal end in males ( Figs. 1 , 6 ); in females and juveniles, very wide serrated tooth near proximal end, small serrated tooth near distal end; row of small teeth sometimes present between proximal and distal teeth in larger specimens ( Figs. 2 , 6 ). Dactylus deflected downwards; robust serrated tooth confined to median portion in males, long serrated tooth in females and juveniles, extending from median portion to near distal end of dactylus ( Figs. 1 , 2 , 6 ).

Pereiopods slim; P4 longest, inflated; P3 longer than P2; P5 shortest. Carinas or serrations on P2 absent; dorsal surface of merus concave. P3 with rugose carina on dorsal surface of merus. P4 with rugose carina extending across dorsal surface of merus; ventral surface inflated; row of small spines extending across ventral surface of merus, usually covered by dense patch of setae; propodus ventral margin usually bicarinate; anterior carina varying from serrated to non-serrated or absent; posterior carina always present and serrated. Dactyli of P2–P4 slightly curved inwards. P5 with dorsal and ventral row of setae from merus to dactylus; ventral portion of merus slightly inflated, lacking row of spines; dactylus straight ( Figs. 1 , 7 ).

Pleon surrounded by small setae in males and females ( Figs. 1 , 2 ). Pleon thickening from segments 2–4, becoming slenderer from 5–6 in males; lateral margins of third and sixth segments concave; telson semicircular, wider than long ( Figs. 1 , 8 ). Pleon of adult female horizontally oval; segments increase in width from first to fourth and decrease from fifth to sixth; telson much wider than long, less wide than sixth segment, about as long as segments, margins discontinuous with shape of rest of pleon ( Fig. 2 ). Pleon of juvenile females vertically oval, somewhat similar to that of males; segments increasing in width from first to third and decreasing from fourth to sixth; telson subtriangular, wider than long. G1 almost reaching end of telson; surrounded by relatively long setae on outer margin; apex curved in approximately 90°; small subdistal tuft of setae forming 45° angle with apex; apex horizontally flattened distally, with small triangular protrusion on median portion ( Fig. 9 ).

Distribution. Western Atlantic— Panama, Venezuela, Tobago and from Amapá to Rio Grande do Sul, Brazil ( Coelho 1997, as Pinnixa aidae ; Bezerra et al. 2006; Mantelatto et al. 2020; Palacios Theil & Felder 2020). Pending further analysis and sampling, we suspect that the limit of distribution in southern Brazil appears to be the north of São Paulo State.

Figures

FIGURE 1. Male topotype of Austinixa aidae (Righi, 1967) (CCDB 3100): (A) dorsal view of the carapace; (B) lateral view of posterior portion of carapace and anterior portion of pleon; (C) antenna; (D) antennule; (E) external face of male telson; (F) external face of male pleon; (G) internal face of left cheliped; (H) external face of left cheliped; (I) dorsal view of right P2; (J) dorsal view of right P3; (K) dorsal view of right P4; (L) dorsal view of right P5.

FIGURE 2. Female topotype of Austinixa aidae (Righi, 1967) (CCDB 3100): (A) dorsal view of carapace; (B) anterior view of frontal region of carapace; (C) posterior view of carapace and pleon; (D) external face of female pleon; (E) internal face of left cheliped; (F) external face of left cheliped; (G) external face of left third maxilliped; (H) enlarged frontal region of carapace with antennae and antennules.

FIGURE 3. Dorsal view of Austinixa aidae (Righi, 1967) and A. bragantina Coelho, 2005: (A) male topotype of A. aidae; (B) dorsal view of the anterolateral margin of the carapace, without branchial ridge, Foz do Rio Juqueriquerê, Caraguatatuba, São Paulo, Brazil (CCDB 3100); (C) female of A. aidae; (D) dorsal view of anterolateral margin of the carapace, with branchial ridge, São Miguel dos Milagres, Porto da Rua, Alagoas, Brazil (CCDB 6555); (E) male topotype of A. bragantina; (F) dorsal view of anterolateral margin of the carapace, with branchial ridge, Ilha Canela, Bragança, Pará, Brazil (CCDB 4542); (G) male topotype of A. bragantina, (H) dorsal view of anterolateral margin of the carapace, without branchial ridge, Ilha Canela, Bragança, Pará, Brazil (CCDB 4542). Scale bars: A, G = 2 mm; B, D–F, H = 1 mm; C = 5 mm.

FIGURE 4. Austinixa aidae (Righi, 1967), SEM of carapace in dorsal view: (A) male topotype of Austinixa bragantina with branchial ridge, Ilha Canela, Bragança, Pará, Brazil (MOUFPE 13411); (B) male topotype of A. aidae without branchial ridge, Foz do Rio Juqueriquerê, Caraguatatuba, São Paulo, Brazil (MZUSP 2233); (C) male of A. bragantina sensu Coelho (2005), with branchial ridge, from Praia de Cumuruxatiba, Prado, Bahia, Brazil (UESC 1124).

FIGURE 5. Austinixa aidae (Righi, 1967) from MOUFPE collection: (A–C) male MOUFPE 13411 (as paratypes of A. bragantina); (D) female dissected MOUFPE 13411 (paratypes of A. bragantina); (E) MOUFPE 13411 (holotype of A. bragantina); (F) male MOUFPE 9329 (from type locality of A. bragantina).

FIGURE 6. Austinixa aidae (Righi, 1967) from MOUFPE collection: (A–B) male MOUFPE 13411, right and left chelipeds, respectively; (C) male MOUFPE 13411, right chelipeds; (D) female dissected MOUFPE 13411, right cheliped; (E) male MOUFPE 9329, right and left chelipeds, respectively; (F) MOUFPE 13410, right cheliped.

FIGURE 7. Pereiopods of Austinixa aidae (Righi, 1967) from MOUFPE collection: (A–B) male MOUFPE 13411 (as paratypes of A. bragantina); (C) male MOUFPE 9329 (type locality of A. bragantina).

FIGURE 8. Pleonites of Austinixa aidae (Righi, 1967) from MOUFPE collection: (A–C) male MOUFPE 13411 (as paratypes of A. bragantina); (D) male MOUFPE 13410 (as holotype of A. bragantina); (E) male MOUFPE 9329 (type locality of A. bragantina).

FIGURE 9. Scanning Electron Microscopy of the G1 tips of Austinixa bragantina Coelho, 2005 and A. aidae (Righi, 1967): (A) topotype of A. bragantina, Ilha Canela, Bragança, Pará, Brazil (MOUFPE 13411); (B) A. aidae sensu Coelho (2005), without branchial ridge, Praia de Cumuruxatiba, Prado, Bahia, Brazil (UESC 1124); (C) A. bragantina sensu Coelho (2005), with branchial ridge, Praia de Cumuruxatiba, Prado, Bahia, Brazil (UESC 1124); (D) topotype of A. aidae with branchial ridge, Foz do Rio Juqueriquerê, Caraguatatuba, São Paulo, Brazil (CCDB 3100); (E) topotype of A. aidae without branchial ridge, Foz do Rio Juqueriquerê Caraguatatuba, São Paulo, Brazil (CCDB 3100). Scale bars: A–C = 30 µm; D, E = 20 µm.