Epipedodromia André, 1932

Guinot, Danièle & Tavares, Marcos, 2003, A new subfamilial arrangement for the Dromiidae de Haan, 1833, with diagnoses and descriptions of new genera and species (Crustacea, Decapoda, Brachyura), Zoosystema 25 (1), pp. 43-129 : 64-70

Genus Epipedodromia André, 1932

( Fig. 7A )

Platydromia Fulton & Grant, 1902a: 57 (pre-occupied by Platydromia Brocchi, 1877 , type species: Platydromia depressa Brocchi, 1877 , junior synonym of Dromidia spongiosa Stimpson, 1858 , see under Platydromia spongiosa ( Stimpson, 1858)) . — Fulton & Grant 1906a: 11; 1906b: 20. — Hale 1925: 412; 1927: 105. — Griffin 1972: 52.

Epipedodromia André, 1932: 180 (replacement name, with same type species: Epipedodromia thomsoni ). — McLay 1993: 224, 225, table 8; 2001b: 2, 7, table 1. — McLay et al. 2001 pro parte: 743.

TYPE SPECIES. — Platydromia thomsoni Fulton & Grant, 1902 by monotypy. Gender: feminine.

SPECIES INCLUDED. — Epipedodromia thomsoni (Fulton & Grant, 1902) .

DISTRIBUTION. — Australia.

DESCRIPTION

Males not examined by the authors.

Carapace wider than long, subpentagonal; dorsal surface flattened, not membranous, with regions not defined; branchial groove indistinct, not marked by tooth. Prominent ledge present posterior to front, and limiting anterior margin of carapace, front and cephalic parts at lower plane and showing as “false front”, marked by hairy ridge and divided into four parts by deep grooves. When viewed from above, carapace quadrate. Lateral margin formed by anterior part (slightly convex and corresponding to lateral border of “false front”), by straight medial part (anteriorly delimitated by notch), and by concave border corresponding to posterolateral margin. Front partly visible dorsally, entire; rostrum truncate medially; pseudorostral teeth eave-like, turned upwards. Proepistome small but marked by raised ridge. Orbits deep; eyes small. No supraorbital and exorbital teeth; suborbital tooth forming thickening. Antenna: urinal article with anterior part of beak very narrow and posterior part shorter and rounded; basal article with exopod and internal corner similarly developed and produced. Mxp3: coxae separated by gap. Pterygostomial region soft.

Thoracic sternite 3 distinctly developed and completely visible. Thoracic sternite 4 forming raised piece, with medial part triangular and lateral parts largely expanded. In females, posterior sternites sharply and vertically tilted to form brood chamber; female sternal sutures 7/8 ending apart; apertures of spermathecae between P1 and P2, at level of episternite 4, and beneath raised medial ridge ( Fig. 7A ).

Male abdomen with all segments free, acutely triangular in shape but telson rounded, obtuse at tip. No vestigial pleopods in males (to be verified). Uropods absent (verified in ovigerous females only). Holding of abdomen by raised knob on P2 coxae. Female abdomen welldeveloped, first three segments positioned dorsally.

Chelipeds without epipod. P2 and P3 longer than chelipeds, smooth. P4 and P5 reduced; P5 longer, its curved merus almost as long as lateral margin of carapace. Subcheliform apparatus formed by single distal propodal spine opposing dactylus.

Carrying behaviour

“Unknown, but probably sponge” ( McLay 2001b: 2, table 1).

REMARKS

Epipedodromia thomsoni has the front and cephalic parts being at lower plane, that provides a somewhat similar appearance than in Desmodromia and Homalodromia and also in Hypoconcha , see under Homalodromia .

4

The examination of male of Epipedodromia thomsoni will show whether the uropods are missing ( McLay 1993: 225, table 8; 2001b: 2, table 1), or are simply reduced to small ventral plates.

The species is characterized by the development of a brood chamber and by direct development. As Hale (1925: 412), we found very few large eggs in the pouch.

Genus Fultodromia McLay, 1993 ( Fig. 8 )

Dromia – Guérin-Méneville 1832: pl. 14, fig. 1. — H. Milne Edwards 1837 pro parte: 170, 177. (Non Dromia Weber, 1795 ).

Cryptodromia – Stimpson 1858 pro parte: 255; 1907 pro parte: 172. — Baker 1907: 180. — Ihle 1913 pro parte: 32. — Montgomery 1931: 413. (Non Cryptodromia Stimpson, 1858 ).

Petalomera – Rathbun 1923a pro parte: 154. — Hale 1927 pro parte: 111, 112. (Non Petalomera Stimpson, 1858 ). Dromidiopsis – Balss 1935: 113. (Non Dromidiopsis Borradaile, 1900 ).

Fultodromia McLay, 1993: 124 , 162, table 3.

TYPE SPECIES. — Dromia nodipes Guérin-Méneville, 1832 by original designation ( McLay 1993: 162). ( Dromia nodipes Lamarck, 1818: 264 is a nomen nudum). Gender: feminine.

A specimen of Dromia nodipes (female 22.5 × 23 mm, MNHN-B 15, rehydrated and now in alcohol) is regarded as the presumed type and selected here as the lectotype. It is not accompanied by any original label indicating the country of origin. This agrees to the question mark in the caption of the figure by Guérin- Méneville (1832: 11) and in the text of H. Milne Edwards (1837: 170). The mention “Cap de Bonne- Espérance” in the MNHN inventory register most probably results from a mistake of a subsequent transcription: it is perhaps useless to assign the reference for Port Esperance or Esperance Bay in South Australia ( McLay 1993: 162). Therefore, the origin of the lectotype remains unknown. However, Fultodromia nodipes is most probably an Australian species, where it has been found by Baker (1907: 180, pl. 25, fig. 1, as Cryptodromia depressa ), Hale (1927: 112, fig. 110, as Petalomera depressa ) and Rathbun (1923a: 154, as P. depressa ).

SPECIES INCLUDED. — Dromia nodipes Guérin- Méneville, 1832 (senior synonym of Cryptodromia tumida Stimpson, 1858 ; Petalomera depressa Baker, 1907 , and Dromidiopsis michaelseni Balss, 1935 ); Cryptodromia tumida var. spinifera Montgomery, 1931 .

DISTRIBUTION. — Australia.

DESCRIPTION

Carapace almost as long as wide, convex; dorsal surface with regions not well-defined; branchial groove indistinct but a tooth just behind it. Anterolateral margin joining exorbital angle and armed with several developed blunt teeth; posterolateral margins nearly straight. Front with deflexed rostral tooth and two prominent pseudorostral teeth; supraorbital and exorbital teeth prominent; suborbital tooth may be developed. Antenna: urinal article with anterior part of beak longer and more acute than posterior ones; basal article with exopod very long and thickened and with internal corner produced, both enclosing two following articles. Mxp3: coxae closely approximated.

Thoracic sternite 3 not visible. Male thoracic sternite 4 with anterior margin bluntly triangular; episternites 4 and 5 narrow. Female sternal sutures 7/8 reaching forward to between coxae of P1; apertures of spermathecae apart, but not separated by wide space. When male abdomen is applied against ventral surface, only a small part of sternite 4 exposed; episternite 4 not visible or only a minute part discernible; episternite 5 not visible.

Male abdomen with all segments free, wide, and with characteristic blunt but developed prominences in latero-posterior angles; telson with base very enlarged and may be markedly concave at tip. Male segment 6 with external borders thickened on anterior half. No vestigial pleopods in males. Male uropods showing as much salient and mobile dorsal plates, with petaloid expansions similar to those of posterior angles of abdominal segments ( Fig. 8 ). Holding of abdomen consisting of a strong serrated prominence on P2 coxa, far from uropods.

Chelipeds with epipod. All pereopods short and thick. P2 and P3 nodular; propodus without distal spine; inner margin of dactylus with spines. P4 and P5 reduced, with terminal apparatus formed by up to two distal propodal spines opposing dactylus; two or three other spines on outer propodal margin.

Male P5 coxa with long mobile penial tube.

Carrying behaviour

Sponges, compound ascidians.

REMARKS

The female sternal sutures 7/8 end wide apart “in a small mound” in Fultodromia nodipes , and “in a transverse ridge” in F. spinifera ( Montgomery 1931: 414, pl. 29, fig. 3a).

Genus Hemisphaerodromia Barnard, 1954 ( Fig. 7B )

Cryptodromia – Stebbing 1918: 56. — Barnard 1950 pro parte: 307, 328. (Non Cryptodromia Stimpson, 1858 ).

Hemisphaerodromia Barnard, 1954: 100 . — Lewinsohn 1979: 10; 1984: 117. — McLay 1993: 124, 159, table 3. — Guinot & Bouchard 1998: 624, 628.

Petalomera – Kensley 1970 pro parte: 110. (Non Petalomera Stimpson, 1858 ).

TYPE SPECIES. — Cryptodromia monodus Stebbing, 1918 by monotypy (senior synonym of Hemisphaerodromia abellana Barnard, 1954 ). Gender: feminine.

SPECIES INCLUDED. — Hemisphaerodromia monodus ( Stebbing, 1918) .

DISTRIBUTION. — Indian Ocean.

DESCRIPTION

Carapace wider than long, rounded/pentagonal, strongly convex; dorsal surface smooth, with regions not well-defined; branchial groove distinct. Anterolateral margin with only blunt small teeth; posterolateral margins straight, with blunt tooth. Front entire and continuous to orbital margin, a small rostral tooth and two eave-like pseudorostral teeth; no suborbital nor exorbital teeth. Antenna: urinal article developed, with only anterior part of beak acute, posterior part being wide; basal article with exopod well developed and internal corner thickly produced, both enclosing two following articles. Mxp3: coxae closely approximated.

Thoracic sternite 3 not visible. Male thoracic sternite 4 with anterior margin truncate. Female sternal sutures 7/8 ending apart behind P2; apertures of spermathecae wide apart on tubercule, at level of episternite 5 ( Fig. 7B ). When male abdomen is applied against ventral surface, only anterior part of sternite 4 and narrow episternite 4 exposed.

Male abdomen with all segments free, wide; telson with base enlarged and bluntly rounded at tip. Male segment 6 with external borders deeply hollowed and much thickened in anterior part. No vestigial pleopods in males. Male uropods showing as markedly salient and mobile dorsal plates. Uropods involved in holding of abdomen, which is particularly efficient, being provided with whole base of P2 coxa which bears a serrated salient ridge, tightly encircled by depression on border of segment 6. Female uropods visible dorsally.

Chelipeds with an epipod. All pereopods short and stout. P2 and P3 lobed; propodus without distal spine; inner margin of dactylus with few tiny spines. P4 and P5 reduced, with terminal apparatus formed by one distal propodal spine opposing dactylus; only one another very small spine on outer propodal margin.

Male P5 coxa with long mobile penial tube.

Carrying behaviour

Compound ascidians.

REMARKS

As pointed out by Barnard (1954) and McLay (1993), Hemisphaerodromia resembles Sphaerodromia only by the shape of carapace, particularly the front. Nevertheless, Hemisphaerodromia is a typical dromiine, with salient dorsal uropods, male P5 coxa bearing a long penial tube, female sternal sutures 7/8 ending behind P2 and apertures of spermathecae rather far from female gonopores on P3 ( Fig. 7B ).

Fultodromia ( Fig. 8 ) and Hemisphaerodromia are close and characterized by uropods showing as salient and mobile dorsal plates. The uropod and the coxal prominence on P2 are near each other in Hemisphaerodromia ( Guinot & Bouchard 1998: fig. 3C, D), not in Fultodromia ( Bouchard 2000: 82, figs 18E, 20D); the abdominal segment 6 is markedly modified on both. In Hemisphaerodromia ( Fig. 7B ) the apertures of spermathecae are located at level of episternites 5 between P2, while in Fultodromia they reach forward between coxae of P1. The terminal carrying apparatus on P4 and P5 also distinguishes the two genera.

Genus Homalodromia Miers, 1884 ( Fig. 9 )

Homalodromia Miers, 1884: 553 . — McLay 1993: 125, 225, table 8; 2001b: 2, 7, table 1. — McLay et al. 2001 pro parte: 740, table 3.

Pseudodromia – Alcock 1900 pro parte: 149. (Non Pseudodromia Stimpson, 1858 ).

Lasiodromia Alcock, 1901: 56 (type species: Homalodromia coppingeri Miers, 1884 ). — Ihle 1913: 51.

TYPE SPECIES. — Homalodromia coppingeri Miers, 1884 by monotypy.

The replacement name Lasiodromia created by Alcock (1901) for Homalodromia Miers, 1884 , because of the resemblance and possible confusion with Homolodromia A. Milne Edwards, 1880 (Homolodromiidae) was unnecessary ( ICZN 1999: article 56.2).

SPECIES INCLUDED. — Homalodromia coppingeri Miers, 1884 , and perhaps another species, Homalodromia unidentata ( Ihle, 1913) (see Takeda 1977: 73; McLay 1993: 227).

DISTRIBUTION. — Indo-West Pacific.

DESCRIPTION

Carapace longer than wide, whole anterior part strongly deflected; rest of dorsal surface flattened, with regions not defined; branchial groove distinct, may be sometimes marked by tooth. Subhepatic area inflated. Eyes and cephalic appendages not visible dorsally. Anterolateral margin convex, may be sometimes with single small tooth oriented ventrally; posterolateral margins convergent. Front particular, at lower plane and appearing quadridentate in counting pseudorostral and supraorbital teeth; rostrum markedly deflexed, without tooth; each prominent acute pseudorostral tooth fused with similarly shaped supraorbital tooth, together forming broad, concave eave. Suborbital tooth acute, long, visible dorsally; exorbital tooth marked. Proepistome small but marked by raised ridge. Antenna: basal article much longer than wide, with enlarged exopod and internal corner similarly strongly produced; following articles well developed. Mxp3: coxae closely approximated. Pterygostomial region soft.

Thoracic sternite 3 not visible dorsally. Thoracic sternite 4 with anterior margin bluntly truncate, in contact with mxp3 coxae. When male abdomen is applied against ventral surface, anterior part of sternite 4 and epsisternite 4 remaining visible. In females, posterior sternites obliquely tilted; female sternal sutures 7/8 ending apart, just at level of P1; apertures of spermathecae at each extremity of tubular curved prominence forming bridge between P1 coxae ( Fig. 9B ).

Male abdomen with all segments free, triangular in shape but with telson very long and obtuse at tip. No vestigial pleopods in males. Male uropods as elongated and mobile dorsal plates, vertically oriented, involved in holding of abdomen; uropods remaining rather developed in females. Abdominal holding provided by particularly high, cupuliform and denticulated prominence on coxa of P2 ( Fig. 9A ), which remains as a vestige in mature females ( Fig. 9B ); on P1 coxa, a small tuberculate prominence.

Chelipeds without epipod, slightly more massive than P2 and P3, none of these verrucose or dilat- ed. P2 and P3 propodus without distal spine, and inner margin of dactylus armed with several small spines. P4 and P5 reduced but unequal; P5 almost as long as P2, merus not so long as lateral margin of carapace, however. Subcheliform apparatus formed by single distal propodal spine opposing the dactylus.

Male P5 coxa with mobile penial tube.

Carrying behaviour

Sponges.

REMARKS

Despite an overall resemblance of the carapace (in particular the front), which permitted the assertion that Homalodromia is most closely relat- ed to Epipedodromia ( McLay 1993: 225) , several characters of the ventral surface of body separate the two genera, notably: 1) sternite 3 not visible in Homalodromia ( Fig. 9 ) (well-developed and completely visible in Epipedodromia , Fig. 7A ); 2) uropods as elongated dorsal plates vertically oriented, constituting a full-lock system with uropods completely involved in abdominal holding (see Guinot & Bouchard 1998: fig. 3B) (uropods absent, at least in ovigerous females, in Epipedodromia ; their absence is to be verified in males); 3) apertures of spermathecae apart, each located at the extremity of tubular prominence forming a bridge just behind P1 coxae ( Fig. 9B ) (apart, beneath raised medial thickening between P1 coxae in Epipedodromia , Fig. 7A ); and 4) female abdomen normally widened (largely expanded and forming a brood chamber in Epipedodromia ).

Homalodromia resembles Dromidiopsis sensu nobis ( Fig. 6 ) by the shape of their male abdomen, presence of uropods shaped as elongat- ed dorsal plates, that are vertically oriented, and abdominal holding provided by crest on P2 coxae. It differs from it by several features: 1) male abdomen with all segments free (segments 5-6 fused in Dromidiopsis ); and 2) apertures of spermathecae apart and located at each extremity of tubular bridge just behind P1 coxae (ending between P1, together on central prominence, in Dromidiopsis ).

Several dromiid genera share with Homalodromia the ventral location of eyes and cephalic appendages: Epipedodromia , Desmodromia and Hypoconcha . McLay (2001b: 2, table 1) compared the first three genera, but the morphology of thoracic sternum was not taken into account. Differences include: 1) the anterior sternites 3 and 4 (in Epipedodromia large sternite 3 present, sternite 4 raised and triangular, at least in females, Fig. 7A ; sternite 3 not exposed and sternite 4 bluntly truncate in Homalodromia , Fig. 9 ); and 2) the shape of uropods (narrow dorsal plates vertically oriented in Homalodromia , Fig. 9A , said to be absent in Epipedodromia , described as dorsal in immature females of Desmodromia ). In addition to the features of carapace and last pairs of pereopods, Hypoconcha is characterized by a peculiar thoracic sternum ( Fig. 19A ), the presence of male vestigial pleopods ( Fig. 19B ), the uropods showing only as minute ventral lobes ( Fig. 19B, C ), a male abdomen that is short and usually flexed at right angles in the middle, sternal female sutures 7/8 which are relatively short and located on tilted surface of posterior part of sternum ( Fig. 19A ), and by the presence of an epipod on P1. All of these differences support the inclusion of Homalodromia , Epipedodromia and Desmodromia in the Dromiinae n. status, and the separation of Hypoconcha in the Hypoconchinae n. subfam.

Figures

FIG. 7. — A, Epipedodromia thomsoni (Fulton & Grant,1902),Australia,Victoria, Port Phillip, 9 × 11 mm (BM 1884-39), thoracic sternum and spermathecae; B, Hemisphaerodromia monodus (Stebbing, 1918), Madagascar, Fort-Dauphin,Decary coll., det.H. abellana Barnard, 1954, 16 × 18 mm (MNHN-B 12725), thoracic sternum and spermathecae.Abbreviations: cx1-cx5, coxae of P1-P5; e4, e5, episternites 4, 5; mxp3, external maxilliped; o, female gonopore; r, medial ridge; s, aperture of spermatheca; 1-3, sternites 1-3; 4-8, sternites 4-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level.Scale bars: 2.5 mm.

FIG. 8. — Fultodromia spinifera (Montgomery, 1931), Moluccas, Pele, stn AN 1/1, 17.5 × 17.5 mm, abdomen (after Bouchard 2000: fig. 18E).Abbreviations:a6, abdominal segment 6; cx1-cx3, coxae of P1-P3; pr, holding prominence; t, telson; u, uropod; 4, sternite 4.Scale bar:1 mm.

FIG. 9. — A, Homalodromia coppingeri Miers, 1884, Seychelles, 5.2 × 5.3 mm (MNHN-B 26130), thoracic sternum with abdomen; B, Homalodromia? coppingeri Miers, 1894, New Caledonia, LAGON, stn 556, 7.8 × 9 mm (MNHN-B 22528), thoracic sternum and spermathecae; note apertures of spermathecae at level of P1, concealed by sperm plug, and vestigial holding prominence on P2 coxa of female. Abbreviations: a6, abdominal segment 6; b, tubular bridge between apertures of spermathecae; cx1-cx4, coxae of P1-P4; e4, episternite 4; mxp3, external maxilliped; o, female gonopore; pr, holding prominence; sp, sperm plug; t, telson; u, uropod; v, vestige of the holding prominence in the female; 4-8, sternites 4-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Scale bar: 1 mm.

FIG. 6. — A, Dromidiopsis tridentata Borradaile, 1903, New Caledonia, LAGON, stn DW 554, ovigerous 12.7 × 12 mm (MNHN-B 22550), thoracic sternum and spermathecae; B, D. australiensis (Haswell, 1882), Australia, Queensland, Cape Bedford, D. J. G. Griffin det., 15.4 × 14 mm (AM P16598), thoracic sternum with abdomen. Abbreviations: a5, a6, abdominal segments 5, 6; cx1- cx5, coxae of P1-P5; e4, episternite 4; mxp3, external maxilliped; o, female gonopore; pr, holding prominence; s, aperture of spermatheca; t, telson (setae covering sternite 4 not shown); u, uropod; 4-8, sternites 4-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level. Scale bars: 2 mm.

FIG. 19. — A, B, Hypoconcha californiensis Bouvier, 1898, Gulf of California, San José Island (MNHN-B 22066); A, 17 × 18 mm, syntype, thoracic sternum, two front views; note sternites 7 and 8 strongly tilted and perpendicular to preceding ones; B, 20.3 × 19.4 mm, syntype, ventral view of abdomen, with asymmetrical, uniramous vestigial pleopods and uropods showing as ventral plates; C, H. panamensis Smith, 1869, Lower California, Bouvier det. H. digueti Bouvier, 1898, Diguet coll., about 32 mm width (MNHN-B 22071), abdomen, ventral view; note uropods showing as setiferous ventral lobes. Abbreviations: a3-a6, abdominal segments 3-6; cx1-cx5, coxae of P1-P5; e4, e5, episternites 4, 5; mxp3, external maxilliped; o, female gonopore; pl, female pleopod (setae incompletely figured); s, aperture of spermatheca; t, telson; u, uropod; v3-v5, vestigial pleopods 3-5; 3-8, sternites 3-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level. Scale bars: A, C, 2.5 mm; B, 1mm.