Deutella incerta ( Mayer, 1903 )

Mauro, Fábio Da Motta & Serejo, Cristiana Silveira, 2015, The family Caprellidae (Amphipoda: Caprelloidea: Caprellidae) from Campos Basin, Southwestern Atlantic, with a key of species occurring in Brazil, Zootaxa 4006 (1), pp. 103-127 : 106-110

Deutella incerta ( Mayer, 1903)

( Figs. 1–3 )

Luconacia incerta Mayer, 1903: 49 –50, pl.2, figs. 11–14; pl, 6, figs. 73–75; pl. 9, figs. 21, 40, 57.— McCain, 1968: 53 –54, 68– 72, figs. 33–35.

Protellopsis stebbingii Pearse, 1908: 30 –32, fig. 4.

Deutella incerta — Steinberg & Dougherty, 1957: 281, 285–286.— Gable & Lazo-Wasem, 1987: 635 –636, fig. 4.—Guerra- García, 2003b: 1062 , fig. 3.—Guerra-García et al. 2006: 164, figs. 9–11.

Material examined: male, 6.32mm, 23º 9' 59,770" S 41º 3' 12,776" W, 105 m MNRJ 24709, female, 5.2mm, 22º 51' 57,512" S 40º 57' 35,058" W, 92m, MNRJ 24710; 1 juvenile, 22º 46' 50,372" S 41º 3' 39,730" W, 78 m MNRJ 24711; 1 juvenile, 22º 4' 9,756" S 40º 7' 5,747" W, 92m, MNRJ 24712; 1 female, 22º 6' 6,272" S 40º 3' 12,696" W, 154m, MNRJ 24713; 1 female, 22º 51' 57,480" S 40º 57' 35,082" W, 92m, MNRJ 24714; 1 female, 1 male 23º 11' 24,493" S 41º 0' 55,751" W, 177m, MNRJ 24715; 1 female, 23º 10' 0,291" S 41º 3' 12,651" W, 107m, MNRJ 24716.

Diagnosis. Male, 6.32mm. Head convex, lacking rostrum; head spine bent forward; pereonite 2 with spine; pereopod 5 6-articulate, inserted at middle part of pereonite 5.

Antenna 1 flagellum 8-articulate; head and pereonite 2 with a pair of dorsal projections with size varying according to onthogenetic growth; gnathopod 2, basis 3 times longer than broad, about 0.75 times pereonite 2 length; ischium subequal to merus and carpus together; merus 2 times length of carpus; side plates present at pereonites 3 and 4, projected ventrally; male abdomen appendages 1-articulate.

Description. Head: Left mandible pars incisiva 5-toothed, lacinia mobilis 4-toothed; mandibular palp 3- articulate, distal article bearing distal setae; last article setal formula 1-6-1. Right mandible pars incisive 5-toothed, lacinia mobilis strongly serrate, row of three plumose setae. Maxilla 1: inner lobe with five setae; palp with four robust setae, and a small medial seta. Maxilla 2: inner lobe with four setae; outer lobe with seven setae. Maxilliped inner lobe with two lateral setae; outer lobe more than 2 times inner lobe length, with five lateral setae; palp 4- articulate; article 2 with five lateral setae; article 3 bearing a crown of six setae; last article slightly serrate.

Thorax: Gnathopod 1 ischium 0.5 times merus length; merus with two ventral setae; propodus subequal to ischium and merus together, bearing two ventral setae; palm serrate with six small proximal setae and two distal ones; dactylus smooth. Gnathopod 2 ischium, merus and carpus subequal in length and width; propodus with large concavity at medial part and bifid process at distal part; dactylus slightly setose. Pereopods 3-4 2-articulate, first article with two distal setae; last article with apical setae. Insertion of pereopod 5 at medial part. Pereopod 5 6- articulate, with merus, carpus and propodus subequal in length and setose, dactylus strong, up to 0.5 times propodus length.

Abdomen: With a pair of lobes; pair of appendages 1-articulate and with 2 apical setae.

Female, 5.2mm. Antenna 1 flagellum 8-articulate; head and pereonites 2 with a pair of dorsal projections; pereonites 3 and 4 with dorsal humps and expanded ventrally, oostegites large, 0.8 times pereonites width. Gnathopod 2 basis length three times width; gnathopod 2 propodus largest width at medio-proximal portion; palm rugged with 15 small setae; abdomen with pair of lobes with three small apical setae, no appendage.

Distribution. Type Locality: off Mobile Bay, Alabama, Gulf of Mexico, 29°24´N, 88°04´W ( Guerra-Garcia, 2003b). Other localities: Bermuda, east coast of North America from Woods Hole, Massachusetts to Strait of Florida; Gulf of Mexico from Cedar Keys, Florida to Yucatan; Virgin Islands; Barbuda; Barbados; Isla de Margarita, Aruba ( Guerra-Garcia, 2003b). Brazil: Campos Basin, Rio de Janeiro, 78–177m (present study).

Ecology. This species has been collected on mangrove roots, Sargassum , Thalassia , sponges, hydroids, alcyonacians, ascidians and it has occasionally been taken in plankton tows ( Guerra-García, 2003b).

Remarks. Deutella currently comprises 12 species, with no previous records in Brazil ( Lowry, 2014). Guerra- García (2002a) described two new species of Deutella for the Indian Ocean: D. antonbruuni and D. indica . In the same year Guerra-García (2002b) described D. philipinensis for the tropical Indo-Pacific and gave a distributional map for the nine species considered for the genus. Later on, Guerra-Garcia (2003b) synonymized Luconacia Mayer, 1903 to Deutella and revised Deutella including eight species. Furthermore, Guerra-García et al. (2006) described D. caribensis and considered Deutella with 12 species, as is currently accepted ( Lowry, 2014). The present material agrees with Deutella incerta description in the presence of pair of dorsal projections on head and pereonite 2, mandibular palp setal formula (1-x- 1) (x=3–10 setae), and male gnathopod 2 with large concavity at medial part followed by a bifid process ( McCain, 1968; Guerra-Garcia, 2003b). From the 12 known species, Deutella incerta resembles D. aspiducha Gable & Lazo-Wasem, 1987 , D. californica Mayer,1890 , and D. venenosa Mayer, 1890 for the presence of dorsal projections on head and pereonite 2 in both males and females. However, in D. aspiducha and D. venenosa there is a single projection on head and on pereonite 2, while in D.

incerta and D. californica there is a pair of projections on these somites. Deutella incerta can be distinguished from D. californica as well as from D. aspiducha by the male gnathopod 2 basis and pereopod 5 dactylus length. A more complete comparison with these close species is given in Table 2 .

Diagnosis. Body elongate; pereopods 3–4 present and 1–2 articulate; pereonite 5 generally reaching pereonites 3– 4 length together; male abdomen with 1 pair of lobes and 1–2 pairs of appendages 1–2 articulated; female with a pair of lobes (modified from Guerra-García, 2004).

Figures

FIGURE 1. Deutella incerta (Mayer, 1903), male, 6.32 mm, Campos Basin, RJ, MNRJ 24709. Scale bar: habitus = 0.5 mm; mx 1, mx 2, mdb (l), mdb (r), mxp = 0.1 mm.

FIGURE 2. Deutella incerta (Mayer, 1903), male, 6.32 mm, Campos Basin, RJ, gn 1, gn 2, p 3, p 5, abd, MNRJ 24709. Young male, 2.4 mm, habitus, MNRJ 24711. Scale bar: gn 1, gn 2, p 3, p 5, abd = 0.1 mm; habitus = 0.3 mm.

FIGURE 3. Deutella incerta (Mayer, 1903), female, 5.2 mm, Campos Basin, RJ, MNRJ 24713. Scale bar: habitus, gn 2 = 0.5 mm; abd = 0.1 mm.

Tables

TABLE 2. Comparison between Deutella incerta and close related species (modified from Guerra-García, 2003 b).

D. aspiducha	D. californica D. incerta	D. venenosa
Mandible palp article 3 setal formula 1-5-1	1-4-1 1-(3-10)-1	1-4-1
Mandibles pars incisiva 6-toothed	5-toothed 5-toothed	5-toothed
Maxilliped palp article 3 distal projection absent	absent absent	present
Pereonite 2 anterolateral present projection	absent absent	Absent
Head projection 1 single	1 pair 1 pair	1 single
Pereonites 2 projections 1 single	1 pair 1 pair	1 single
♂ pereonite 2 length/Gnathopod 2 basis 2:1	0.5:1 1:1	1:1
Pereopod 5 dactylus length minute	minute ½ lenght of propodus	½ lenght of propodus
Liropus Mayer, 1890
Type species: Liropus africanus Mayer, 1920