Dardanus venosus (H. Milne Edwards, 1848 )

Lima, Daniel, Tavares, Marcos & Jr, Joel Braga De Mendonça, 2019, Paguroids (Decapoda: Anomura: Diogenidae and Paguridae) of the remote oceanic Archipelago Trindade and Martin Vaz, off southeast Brazil, with new records, description of three new species and zoogeographical notes, Zootaxa 4694 (1), pp. 1-63 : 14-19

Dardanus venosus (H. Milne Edwards, 1848)

( Figs. 5A, B, E, F , 6 A–D, 7A–F)

Pagurus venosus H. Milne Edwards, 1848: 61 ; Stimpson 1859: 82.

Pagurias insignis .— Benedict 1901: 141 [in part] [not Dardanus insignis (de Sausurre, 1858) ].

Pagurus arrosor .— Moreira 1901: 24 [not Dardanus arrosor (Herbst, 1796) ].

Pagurus arrosor var. divergens Moreira, 1905: 133 [reprint p. 13], pl. 4, fig. 1; Forest & de Saint Laurent 1968: 49; Biffar & Provenzano 1972: 799.

Dardanus arrosor divergens .— Zariquiey Alvarez 1952: 21, figs. 1, 2 [= Dardanus arrosor (Herbst, 1796) , not Dardanus venosus (H. Milne-Edwards, 1848) ].

Dardanus arrosor var. Divergens .— Gordan 1956: 313

Dardanus venosus .— Verrill 1908: 441, figs. 58, 59, pl. 26, figs. 4a, 5a [in part]; Rathbun 1919: 329; Schmitt 1924: 95; 1935: 201, fig. 62 [in part]; 1936: 376; Holthuis 1959: 153; Provenzano 1959: 374, fig. 6 [in part]; 1960: 119; 1961: 153; 1963: 11, figs. 1–5; Forest & de Saint Laurent 1968: 94; Ross & Sutton 1968: 380; Türkay 1968: 250; Cutress & Ross 1969: 225, pl. 1, figs. a, b; Cutress et al. 1970: 371; Biffar & Provenzano 1972: 778, figs. 1b, 2b, 3b, 4b, 5a, 6a; Coelho & Ramos- Porto 1986: 50; Rieger 1998: 420; Melo 1999: 64, fig. 20; Batista-Leite et al. 2003: 227; Souza & Serejo 2007: 342, fig. 3; McLaughlin et al. 2010: 21; Lemaitre & Tavares 2015: 453, tab. 1; Nucci & Melo 2015: 337 , figs. 3c, 4e.

Pagurus insignis .— Bouvier 1918: 6 [not Dagurus insignis (de Sausurre 1858) ].

Trindade and Martins Vaz, and Vitória-Trindade Seamounts specimens. 1 male sl 0.9 mm, 1 female sl 7 mm ( MZUSP 36044 ), Brazil, off Espirito Santo, Martin Vaz Island, stn 1 Sedimento Coral , 20°28’26.98”S, 28°51’20.98”W, C.H. Guimarães coll., 22.i.2012, SCUBA, 19.2 m ; 1 female sl 10.1 mm ( MZUSP 36050 ), Brazil, off Espírito Santo, Trindade Island, Praia das Orelhas , 20°29’40.2”S, 29°20’32.9”W, J.B. Mendonça coll., 23.vii.2015, SCUBA, 14.6 m ; 1 female sl 7.0 mm ( MZUSP 36043 ), idem, Enseada dos Portugueses, stn Farol , 20°29’52.3”S, 29°19’15.6”W, J.B. Mendonça coll., 08.xi.2014, SCUBA, 12.9 m ; 1 female sl 4.8 mm ( MZUSP 36045 ), idem, Laje Enseada Noroeste , stn 32, 20°29’52.3”S, 29°19’15.6”W, C.H. Guimarães coll., 18.ii.2012, SCUBA, 21.7 m ; 1 male sl 3.9 mm ( MZUSP 36061 ), idem, Praia dos Cabritos , 20°29’32.0”S, 29°19’46.5”W, J.B. Mendonça coll., 14.vi.2012 ; 1 female sl 20.0 mm ( MZUSP 36040 ), idem, Praia da Calheta, 20°30’26.1”S, 29°18’44.2W, J.B. Mendonça coll., 03.vii.2012 ; 1 ovigerous female sl 9.4 mm ( MZUSP 36047 ), idem, Ponta da Calheta , 20°30’18.72”S, 29°18’31.67”W, J.B. Mendonça coll., 11.xi.2014, SCUBA, 16 m ; 1 female sl 9.0 mm ( MZUSP 36049 ), idem, Praia da Calheta , stn SECON, 20°30’29.9”S, 29°18’43.7”W, J.B. Mendonça coll., 18.vi.2012, SCUBA, 12.3 m ; 1 male sl 7.6 mm ( MZUSP 36041 ), idem, Ponta da Calheta , 20°30’18.72”S, 29°18’31.67”W, J.B. Mendonça coll., 11.xi.2014, SCUBA, 16 m ; 1 male sl 6.3 mm ( MZUSP 36046 ), idem, Ponta da Calheta , J.B. Mendonça coll., 04.viii.2015, Rede de espera, ± 30 m ; 1 male ( MZUSP 36042 ), idem, Ponta da Calheta , 20°30’18.72”S, 29°18’31.67”W, J.B. Mendonça coll., 22.x.2014, SCUBA, 15.8 m ; 1 male sl 7.0 mm ( MZUSP 36048 ), idem, Praia do Príncipe , 20°31’20.1”S, 29°18’34.7”W, J.B. Mendonça coll., 19.vi.2012, SCUBA, 12.2 m ; 1 male sl 6.9 mm ( MZUSP 36051 ), Brazil, Espírito Santo, Vitória-Trindade Seamounts Chain, Mount Dogaressa , stn 25/ DC 43 , 20°51’S, 33°45’W, TAFF MD 55 BRÉSIL 1987, 63 m, 17.v.1987 .

Comparative material examined. Dardanus venosus : 1 female sl 3.2 mm, 1 female sl 3.4 mm ( MZUSP 343010 ), Dominican Republic, La Altagracia, Bávaro, Paradise, stn Mergulho 1, 18°41’03.75”N, 68°23’03.75”W, L.R. Simone coll., 19.xi.2014 , SCUBA, 15 m; 1 female sl 13.7 mm ( MZUSP 8853 ), Brazil, Rio Grande do Norte, Rocas Atoll, Norte-Nordeste I 1967 , R/V “ Almirante Saldanha ”, stn 1662A, 03°53’8”S, 33°46’6”W, 25 m, 09.x.1967 ; 1 male sl 15.1 mm, 1 male sl 13.6 mm ( MZUSP 14568 ), Brazil, Pernambuco, Fernando de Noronha , 22.vii.1999 ; 1 male sl 4.1 mm, 1 male sl 4.0 mm, 1 male sl 5.3 mm ( MZUSP 18076 ), Brazil, Paraíba, João Pessoa, Naufrágio do Queimado , 07°05.070’S, 34°44.852’W, L.R. Simone coll., SCUBA, 15 m ; 1 female 9.6 mm ( MZUSP 16174 ), Brazil, Paraíba, João Pessoa , Tambaú, 22.vii.2001 , 1 m; 1 male sl 7.2 mm ( MZUSP 7490 ), Brazil, Pernambuco, Ponta da Pedra , Montouchet coll., 30.viii.1970 ; 1 male sl 15.6 mm ( MZUSP 7215 ), Brazil, Pernambuco, Suape , stn 1, 02.iii.1978 ; 1 female sl 14.9 mm ( MZUSP 7214 ), Brazil, Pernambuco, Suape, stn 9, iv.1965 ; 1 male sl 10 mm ( MZUSP 12815 ), Brazil, Alagoas, Maceió, Praia dos Morros de Camaragibe , 15.ix.1997 ; 1 female sl 10 mm ( MZUSP 12816 ), Brazil, Alagoas, Paripueira, 10.vii.1998 ; 1 female sl 12 mm ( MZUSP 28080 ), Brazil, Bahia, Boipeba, Foz do Rio Catu , stn 2, 13°39.556’S, 38°53.988’W, Tavares et al. coll., 16.ix.2012 ; 1 male sl 8.5 mm ( MZUSP 7506 ), Brazil, Bahia, Salvador, Exp Leste I, R/V “ Almirante Saldanha ”, stn 1891A, 13°38’05”S, 38°45’0”W, 49 m, 23.ix.1968 ; 1 male sl 30 mm ( MZUSP 21461 ), Brazil, Bahia, Minerva bank, 17°03.108’S, 37°37.216’W, J. Coltro coll., 12, viii.2012 , 69 m; 1 male sl 0.9 mm, 1 female sl 7 mm ( MZUSP 36044 ) , 1 male sl 15.7 mm ( MZUSP 12974 ), Brazil, Espírito Santo, Vitória, Ilha do Boi , R.C. Nalesso coll., 21.v.1997 ; 1 male sl 6.1 mm ( MZUSP 16400 ), Brazil, Espírito Santo, Guarapari, xi-xii.2003 ; 1 male sl 11.2 mm ( MZUSP 36032 ), Brazil, Rio de Janeiro, Búzios, Praia de Manguinhos , E. Figueiredo coll., 03.x.1985 ; 1 male sl 15.1 mm ( MZUSP 16489 ), Brazil, Rio de Janeiro, Praia de Itaipú , M. Moscateli coll., ii.1985 ; 1 male sl 8.1 mm, 1 male sl 8.3 mm, 1 female sl 7.8 mm, 1 male sl 7.5 mm, 1 male sl 9.2 mm, 1 female sl 8.5 mm ( MZUSP 8665 ), Brazil, Rio de Janeiro, Praia de Itaipú, W. Vergara F. coll., 10.i.1987 , 2 m; 1 male sl 18 mm, 1 female sl 7.9 mm, 1 female sl 7.5 mm ( MZUSP 8664 ), Brazil, Rio de Janeiro, Praia de Itaipú, W. Vergara F. coll., 10.i.1987 , 2 m; 1 male sl 12.0 mm ( MZUSP 36039 ), Brazil, Rio de Janeiro, Praia de Itaipú , M.D. Tavares coll., 22.i.1982 ; 1 male sl 9.4 mm, 1 male sl 6.9 mm, 1 male sl 5.2 mm, 1 male sl 6.7 mm, 1 female sl 4.1 mm ( MZUSP 36028 ), Brazil, São Paulo, Ilha Bela, Ilha Vitória, Saco da Professora , stn Aquário, Alves & Cobo coll., iii.2006 , SCUBA, 7 m; 1 male 7.6 mm ( MZUSP 36037 ), Brazil, Santa Catarina, Ilha do Arvoredo, Andrea-FURG coll .

Dardanus imperator ( Miers, 1881) : 1 male, 1 female (MZUSP 37955), Saint Helena, Papa Nui Wreck, Judith Brown coll., 13.i.2014, SCUBA.

Dardanus fucosus Biffar & Provenzano, 1972: 1 male sl 3.5 mm (MZUSP 36036), Dominican Republic, La Altagracia, Bávaro, Paradise, stn Mergulho 1, 18°41’03.75”N, 68°23’03.75”W, L.R. Simone coll., 19.xi.2014, SCUBA, 15 m; 1 female sl 3.8 mm, 1 female sl 5.1 mm ( MZUSP 8855 ), Brazil, stn 1910A II, NOAS NNE II, R/V “ Almirante Saldanha ” ; 1 female sl 10.5 mm ( MZUSP 8854 ), Brazil, Pará , Foz do Rio Amazonas, NOAS NNE II 1968 , R/V “Almirante Saldanha”, stn 1892A, 1°45’0”N, 48°18’0”W, 56 m, 01.v.1968.

Type locality. Guadeloupe, Caribbean Sea .

Distribution. Bermuda, Florida, Antilles, Panama, Venezuela, Suriname, and Brazil (from Amapá to São Paulo. Oceanic islands and seamounts: Rocas Atoll, Fernando de Noronha ( Nucci & Melo 2015), Seamounts (Almirante Saldanha, Dogaressa, Minerva), Trindade and Martin Vaz, present study).

Remarks. Seven species of Dardanus are currently known from the Atlantic: D. arrosor (Herbst 1796) (COS); D. calidus ( Risso, 1827) (EA); D. fucosus Biffar & Provenzano, 1972 (WA); D. imperator ( Miers, 1881) (ASC, STH); D. insignis (de Saussure, 1858) (WA); D. pectinatus ( Ortmann, 1892) (EA); and D. venosus (H. Milne Edwards, 1848) (WA). The specimens from the oceanic island of Trindade are herein assigned to D. venosus .

As already noted by Biffar & Provenzano (1972), D. venosus , D. fucosus and D. imperator closely resemble one another morphologically, and can be separated from their other Atlantic congeners in having the dorsal surface of the cheliped palm with tubercles surrounded by short setae, whereas in D. arrosor , D. insignis , and D. pectinatus it is provided with spinous transverse ridges or scutes.

Dardanus venosus can be distinguished from D. fucosus in having no groove along the ventral margin of the left P3 dactylus (vs. distinct groove present in D. fucosus ). Asakura et al. (2003) suggested that the fleshy membranous protuberances on the female pleon (referred to as thin plates in Asakura & Hirayama 2002) are species-specific in Dardanus . Additional references in the literature to the fleshy membranous protuberances are very scarce and its function remains unknown (viz. Ayón-Parente & Hendrickx 2009). Females of D. venosus and D. fucosus do indeed possess two fleshy membranous protuberances (fmp) between both Pl2–Pl3 and Pl4–Pl5 (in one female of D. venosus examined herein the protuberances between Pl2–Pl3 were lacking, and there was only one protuberance between Pl4–Pl5, instead of two). Adult females of D. venosus and D. fucosus can be differentiated from each other in that the fmp between both Pl2–Pl3 and Pl4–Pl5 have rather entire margins in D. venosus ( Fig. 6A, B ), whereas in D. fucosus the fmp are distinctly lobate ( Fig. 6C, D ). In females of D. venosus and D. fucosus , the fmp between Pl2–Pl3 are distinctly smaller than the protuberances between Pl4–Pl5. In D. venosus , the male fmp, when present, resembles the female protuberance in having entire margins ( Fig. 6E, F ). Males of D. venosus usually lack the fmp between Pl2–Pl3 (all males from Trindade were devoid of protuberances, whilst a few males from the Brazilian continental shore had one small protuberance). The fmp between Pl4–Pl5 is also absent in most males (only a few males from both Trindade and the continental shore had one fmp instead of none). The fleshy membranous protuberance formula does not support the separation of the population from Trindade into a different species from D. venosus .

According to Biffar & Provenzano (1972), D. imperator can be distinguished from D. venosus and D. fucosus in having more prominent grooves and ridges on the P3 propodus. However, the development of the propodal grooves and ridges is actually highly variable. Manning & Chace (1990: 40) reported that the cross ridges on the left P3 propodus are distinctly concave in D. imperator , conversely to the holotype of D. imperator illustrated by Biffar & Provenzano (1972: fig. 4C) in which the propodal cross ridges seem to be convex in cross section. In the male and female of D. imperator (MZUSP 37955) from St. Helena the cross ridges are only slightly concave ( Fig. 6E ). In D. venosus from Trindade the cross ridges on the propodus of the left P3 are consistently deeply concave, whilst in a large series of males and females from the Brazilian coast the cross ridges vary in the degree of concavity both below and above the longitudinal middle ridge ( Fig. 6 B–D). Similarly, the development of the propodal grooves and cross ridges are variable between the female and male from Bermuda and Belize, respectively ( Manning & Chace, 1990: fig. 21A, B). Therefore, the effectiveness of the propodal grooves and ridges for distinguishing between D. venosus and D. imperator remains unsettled and deserves further investigation.

Despite the paucity of morphological characters to reliably diagnose D. venosus and D. imperator , these two species display distinct color patterns. In the original description of D. venosus, H. Milne Edwards (1848) described D. venosus as being “... yellowish, stained with red, which on the fingers and inner surfaces of the palms form a reticulated pattern of thin lines, so as to resemble capillary veins” [the species name, venosus , allude to this feature]. H. Milne Edwards (1848) also referred to the presence of “redish, stiff setae on the ambulatory legs”. Although the color pattern can vary from pale red to blood red in D. venosus ( Fig. 7 A–F), the striking reticulated pattern of reddish lines (venation) which covers almost completely all surfaces of the shield, chelipeds and pereopods allows for its straightforward recognition. On the other hand, D. imperator can be promptly differentiated from D. venosus in possessing a distinctive deep purple shield, purple-banded ocular peduncles, chelipeds and ambulatory legs, and by a faint reticulated reddish pattern on the ventral faces of ambulatory legs, and inner surfaces of the cheliped carpus and palm extending onto fingers ( Fig. 8 A–D). Manning & Chace (1990) provided a detailed description of the color in life of D. imperator .

Figures

FIGURE 5. (A–F) Pleonal fleshy membranous protuberance (fmp) located between the female and male pleopods. (A, C) female’s fmp between Pl2 and Pl3. (B, D) female’s fmp between Pl4 and Pl5. (E) male’s fmp between Pl2 and Pl3. (F) male’s fmp between Pl4 and Pl5. (A, B, E, F) Dardanus venosus (H. Milne Edwards, 1848). (A, B) female sl 20 mm from Trindade Island (MZUSP 36040). (E, F) male sl 18.0 mm from Rio de Janeiro (MZUSP 8664). (C, D) Dardanus fucosus Biffar & Provenzano, 1972, female sl 10.5 mm from Pará, Brazil (MZUSP 8854). Scale bars: A–C, 2.5 mm; D = 5.0 mm; E, F, 1.0 mm.

FIGURE 6. Propodus of left P2, lateral view. (A–D) Dardanus venosus (H. Milne Edwards, 1848). (E) Dardanus imperator (Miers, 1881). (F) Dardanus fucosus Biffar & Provenzano, 1972. (A) female sl 20.0 mm, from Trindade Island (MZUSP 36040). (B) female sl 14.9 mm from Pernambuco, Brazil (MZUSP 7214). (C) male sl 15.1 mm from Fernando de Noronha Island, Brazil (MZUSP 14568). (D) male sl 15.7 mm from Espírito Santo, Brazil (MZUSP 12974). (E) male sl 8.0 mm from St. Helena Island (MZUSP 37955). (F) female sl 10.5 mm from Pará, Brazil (MZUSP 8854).

FIGURE 7. (A–F) Dardanus venosus (H. Milne Edwards, 1848). (A) Martinique, Caribbean Sea, photograph by Y. Buske. (B) Couves Island, Brazil, photograph by D.F.R. Alves. (C) Guadeloupe, Caribbean Sea (MNHN IU–2013–4404), photograph by J. Poupin and L. Corbari. (D) Glover’s Reef, Belize, photograph in situ by P. Ryan. (E) Saint Martin, Caribbean Sea, photograph by A. Anker. (F) male sl 7.6 mm from Trindade Island (MZUSP 36041), photograph by J.B. Mendonça Jr.

FIGURE 8. (A–D) Dardanus imperator (H. Milne Edwards, 1848). (A, B) St. Helena Island. (C, D) Ascension Island. Photographs by J. Brown (A, B, D) and P. Wirtz (C).