PHYLLODORIPPINAE, Guinot, 2023

Guinot, Danièle, 2023, A new subfamily classification of the highly diversified Dorippidae H. Milne Edwards, 1837 (Crustacea, Decapoda, Brachyura, Dorippoidea), using morphological, molecular and palaeotonlogical data, with special emphasis on its unique female reproductive system, Zoosystema 45 (9), pp. 225-372 : 288-291

Subfamily PHYLLODORIPPINAE n. subfam.

TYPE GENUS. — Phyllodorippe Manning & Holthuis, 1981 (type species by original designation: Dorippe armata Miers, 1881 ). Monotypic.

DESCRIPTION

Carapace ( Fig. 29A, B )

Carapace short, clearly wider than long. Dorsal surface without large tubercles, spines or elevations (only granules), but with raised tripartite ridge on swollen branchial region. Meso-, meta-, urogastric regions weakly demarcated. Precervical groove shallow; cervical groove well defined; branchiocardiac groove moderately deep. Antero- and posterolateral margins delimited by marked epibranchial tooth, very developed in large specimens. Front bidentate, consisting of two low obtuse teeth; median emargination wide, flat. No inner orbital teeth or lobes. Outer orbital teeth reaching slightly further forward than front. Lower margin of orbit between extra- and infraorbital teeth smooth, large U-shaped. Superior margin of orbit with fissure. Partial and weak exposure of pleurites 5-7 with smooth texture; margin of carapace lying in small guter at this level. Carapace posterior rim not extending laterally along posterolateral margin and lined posteriorly by narrow, straight, integrated strip in males and females.

Illustrations: Phyllodorippe armata: Monod 1933b : fig. 4A, as Dorippe armata (reproduced by Manning & Holthuis 1981: fig. 4j); Capart 1951b, as D. armata ; Monod 1956: fig. 102, erroneously as D. lanata (reproduced by Manning & Holthuis 1981: fig. 4i; by Sin et al. 2009: fig. 3I); Capart 1951b: fig. 7, as D. armata .

Cephalic structures ( Figs 29A ; 30A )

Eyestalks rather short, not reaching beyond outer orbital teeth. Antennule partly folded, distal part of antennular article being out fossa. Antenna directed entirely forward; articles 2+3 rather narrow; article 4 slightly enlarged; article 5 elongate; flagellum rather long.

Oxystomatous disposition ( Fig. 30 A-C)

Exposed portion of mxp1 endopod beyond extent of mxp3 short. Opening of exhalant channels barely reaching frontal margin, thus not visible in dorsal view.

Illustrations: Phyllodorippe armata: Monod 1933b : fig. 4A, B, as Dorippe armata ; 1956: figs 102, erroneously as D. lanata (reproduced by Manning & Holthuis 1981: fig. 4i), 104.

Pereiopods ( Figs 29A, B ; 30A,C )

Left and right chelipeds equal and similar in both sexes at small size; strong sexual dimorphism: pronounced heterochely in young adult males of 20 mm carapace width, with glabrous major chela becoming enormous.

Illustrations: Phyllodorippe armata: Miers 1881 : fig. 4, 4a, as Dorippe armata ; Monod 1956: fig. 105, as D. armata ; Manning & Holthuis 1981: fig. 4a.

P2, P3 meri without spines on dorsal margin, only with several striated rows on raised ridges, resulting in a keeled appearance; dactyli narrow and slightly twisted, fringed with short hairs in basal half of upper margin in both sexes.

Both P4, P5 reduced, narrow and much setose; P5 thinner and shorter than P4.

Illustrations: Phyllodorippe armata: Monod 1933b : fig. 3A, B, as Dorippe armata .

Thoracic sternum ( Figs 29C, D ; 30 )

Thoracic sternum extremely wide. Sternites 1 and 2 forming short pentagonal shield, with thickened lateral margins; sternite 1 with small blunt median portion visible dorsally, remaining part passing under mxp3 and being concealed; sternite 2 separated from sternite 3 by lateral notch and median depression; sternite 3 very broad, with two extended lateral portions: a foliaceous lobe connected to pterygostome, the other extending along arthrodial cavity of P1; sternite 4 with thick oblique ridge on each part. Sutures 4/5-7/8 interrupted; suture 3/4 only lateral, deep, ending in marked boutonniere; sutures 4/5 and 5/6 with short interruption points; suture 5/6 abruptely curved backwards, with narrow curve accommodating press-button. Female thoracic sternum almost vertically tilted backwards at level of ridge crossing whole sternite 6, which marks delimitation between the two distinct parts of thoracic sternum; sternite 8 with erect axial spine ( Fig. 29D ).

Pleon and telson ( Figs 29 A-C; 30B)

Sterno-pleonal cavity short and very narrow. Male pleon with all somites free, first three somites exposed dorsally; first three and part of 4 exposed in females; surface with only low, very blunt elevations especially on male somite 3; somites 2 and 3 granular; telson very short, exceeding suture 5/6. Female pleon as on Figure 29C, D .

Illustrations: Phyllodorippe armata: Monod 1933b: 36 , as Dorippe armata ; 1956: figs 106, 107, as D. armata .

Pleonal-locking mechanism by press-button ( Figs 29C, D ; 30C, D )

Press-button prominent, located in abruptely curved sternal suture 5/6, effective in both sexes, even in mature females.

Additional female pleonal-retention mechanism ( Fig. 29B )

In females, strong retention by small spine of exposed dorsal portion of sternite 8 overhanging pleonal somite 2; small telson wedged between abrupt slopes of sterno-pleonal cavity at level of sternite 5.

Male gonopore and penis

Male gonopore coxal. Penis rather short ( Monod 1933b: fig. 5C, as Dorippe armata ). Note that the penial region figured by Guinot et al. (2013: fig. 15E) was based on a misidentified specimen and thus represents the condition of Medorippe lanata as shown in fig. 15B, D of the same paper.

Gonopods ( Figs 30C, D ; 31H )

G1 long, basally twisted, very slender, S-curved, second half horny-looking, with large, lobiform inverted triangular subdistal appendage, and ending in narrow acute point; no basal lobe.

Illustrations: Phyllodorippe armata: Monod 1933b : fig. 3H, as Dorippe armata (reproduced by Manning & Holthuis 1981: fig. 4k-l; by Sin et al. 2009: fig. 4I).

G2 rather long, straight, with indistinct partition.

Vulvae ( Figs 29C, D ; 32I )

Females already ovigerous at size of 7.0 × 10.0 mm. Vulvae (hitherto unknown and shown here for the first time) rather distant from distal part of setose sternal ridge, situated on raised slopes of narrow sterno-pleonal cavity, rather close to each other, in the shape of narrow slit.

Female reproductive system

Not known.

DISTRIBUTION AND HABITAT

Phyllodorippe armata lives in shallow waters on sand, mud or shell bottoms ( Zariquiey Alvarez 1968: 313, as Dorippe armata ; Monod 1956: 96; Manning & Holthuis 1981: 34, 35), being able to tolerate low salinities ( Balss 1921: 48; Voss 1966: 37; Sourie 1954, all as D. armata ). Tropical and subtropical eastern Atlantic, off West Africa, from many localities between Spanish Sahara and Angola ( Capart 1951b, as D. armata ; Le Loeuff et al. 2000); from Cape Verde Islands (A. Milne-Edwards & Bouvier 1900, as D. armata ; Gonzáles 2018: 421, table 3), the Canary Islands (García-Isarch & Muñoz 2015) and islands off the Gulf of Guinea, São Tomé and Principe ( Forest & Guinot 1966: 50, as D. armata ). Also off Nigeria and Gabon ( Henriksen 2009: 38; Dessouassi et al. 2018). Phyllodorippe armata cohabits with Medorippe lanata along the West-African coast, in Dahomey (Crosnier coll. et det., MNHN-IU-2018-5196 (= MNHN-B16380 pro parte), Ghana (in the same station 24, see Forest & Guinot 1966: 36, 50, as Dorippe armata ), Sierra Leone, off the Ivory Coast ( Forest & Guinot 1966: 50, as D. armata ; Manning & Holthuis 1981: 36, 338; Le Loeuff & Intès 1999: 547), Nigeria ( Manning & Holthuis 1981: 36) and Angola ( Guinot & Ribeiro 1962, as D. armata ). The Phyllodorippe armata from Dahomey recorded as Dorippe armata by Crosnier (1964: 32, 38) actually contains both species M. lanata and P. armata [fig. on pl. A is M. lanata , apparently taken from Monod (1956)].

CARRYING BEHAVIOUR

The carrying behaviour of a dorippid that is probably Phyllodorippe armata is only documented by the report of a crab from the mangrove of Crique Banjia, Gabon, described with a leaf held on its back with the last legs ( Pechüel-Loesche 1882: 288), a habit somewhat similat to that found in Neodorippe Serène & Romimohtarto, 1969 .

REMARKS

Examination of numerous specimens in the MNHN, which holds large number of both Medorippe lanata ( Medorippinae n. subfam.) and Phyllodorippe armata ( Phyllodorippinae n. subfam.), confirms that P. armata is a much smaller species than M. lanata : it reaches only a small size, with an ovigerous female 10 mm in width (A. Milne-Edwards & Bouvier 1900: 33, as Dorippe armata ).

Figures

FIG. 29. — Phyllodorippinae n. subfam. Phyllodorippe armata (Miers, 1881), Guinean Trawling Survey,ZRC 2009.0413 (ex MNHN-B24202). A, ♂ 12.3 × 16.2 mm, habitus; B-D, ovigerous ♀ 11.9 × 16.6 mm. B, habitus; C, thoracic sternum and pleon; D, thoracic sternum, vulvae and spine on sternite 8.

FIG. 30. — Phyllodorippinae n. subfam. Phyllodorippe armata (Miers, 1881), ♂ 12.3 × 16.2 mm, Guinean Trawling Survey, ZRC 2009.0413 (ex MNHN-B24202): A, both chelae; B, thoracic sternum and pleon; C, thoracic sternum without pleon; D, G1 and press-buttons.

FIG. 31. — Diversity of G1s in the seven dorippid subfamilies (schematic drawings): A, Dorippinae n. stat. (Dorippe quadridens); B, Dorippoidinae n. subfam. (Dorippoides facchino); C, Medorippinae n. subfam.(Medorippe lanata); D-F, Heikeopsinae n.subfam.:D, Heikeopsis?japonica; E, Neodorippe callida; F, Nobilum histrio; G, Paradorippinae n. subfam. (Paradorippe cathayana); H, Philippidorippinae n. subfam. (Philippidorippe philippinensis); I, Phyllodorippinae n. subfam. (Phyllodorippe armata). (A-H, after Holthuis & Manning 1990; I, after Manning & Holthuis 1981). From Sin et al. (2009: fig. 4). Setae not always figured.

FIG. 32. — Diversity of vulvae in the seven dorippid subfamilies (schematic drawings): A, Dorippinae n. stat. (Dorippe quadridens); B, Dorippoidinae n. subfam. (Dorippoides facchino); C, Medorippinae n.subfam.(Medorippe lanata); D-F, Heikeopsinae n. subfam.;D, Heikeopsis?japonica; E, Neodorippe callida; F, Nobilum histrio; G, Paradorippinae n. subfam. (Paradorippe cathayana); H, Philippidorippinae n. subfam. (Philippidorippe philippinensis); I, Phyllodorippinae n. subfam. (Phyllodorippe armata, ♀ 13.0 × 19.0 mm, Guinean Trawling Survey, MNHN-IU-2021-8731 [= MNHN-B24199]). Setae represented only on B. A-H, modified from Holthuis & Manning (1990).