Mantacaprella macaronensis

Vázquez-Luis, Maite, Guerra-García, José M., Carvalho, Susana & Gonzalez, Lydia Png-, 2013, Mantacaprella macaronensis, a new genus and species of Caprellidae (Crustacea: Amphipoda) from Canary Islands and Cape Verde, Zootaxa 3700 (1), pp. 159-172 : 161-168

Mantacaprella macaronensis n. sp

( Figs. 2 –7)

Type material: Holotype, mature male (used for drawings of lateral view, antennae, gnathopods, pereopods and abdomen) (vial and two slides, dissected) (vial: MNCN 20.04/9150, slide 1: MNCN 20.04/9151, and slide 2: MNCN 20.04/9152), Arinaga (N 27º51'52.9'', W 015º23'01.0''), Gran Canaria, Canary Islands, 10 meters deep, seagrass Cymodocea nodosa , November 2011.

Paratype, mature female, collected together with the holotype (used for drawings of lateral view, gnathopod 2 and abdomen) (vial and one slide, not dissected) (vial: MNCN 20.04/9153, and slide: MNCN 20.04/9154).

Other paratypes (collected together with the holotype):

Dissected and/or figured: 2 mature males dissected (2 vials and 2 slides) Male 1, vial: MNCN 20.04/9155, slide: MNCN 20.04/9156; Male 2, vial: MNCN 20.04/9157, slide: MNCN 20.04/9158—used for drawings of mouthparts—and 2 mature females dissected (2 vials and 2 slides). Female 1, vial: MNCN 20.04/9159, slide: MNCN 20.04/9160; Female 2, vial: MNCN 20.04/9161, slide: MNCN 20.04/9162; 3 juveniles (used for drawings of lateral view) MNCN 20.04/9163, MNCN 20.04/9164 and MNCN 20.04/9165. Not dissected, not figured: 5 mature males (MNCN 20.04/9166), 7 mature females (MNCN 20.04/9167).

Additional material examined: Canary Islands: 10 mature males, 24 juvenile males, 25 mature females, 13 premature females, 20 juveniles, collected from Arinaga (type locality) together with the type material; 1 mature male, 1 mature female, 2 premature females collected from Veneguera, Gran Canaria, 11 m, seagrass Cymodocea nodosa , November 2011; 7 specimens collected from Gando 2, Gran Canaria, 14–15 m, Caulerpa prolifera dominated beds, November 2011 and October 2012; 9 specimens collected from Risco Verde, Gran Canaria, Canary Islands, 11 m, seagrass Cymodocea nodosa , November 2011; 17 specimens collected from Cabrón, Gran Canaria, 9 m, seagrass Cymodocea nodosa , October 2012.

Cape Verde: 10 mature males, 7 juvenile males, 11 mature females, 3 premature females, 11 juveniles collected from Kwarcit, Santa Maria, Sal Island, 25 m, artificial substrate, March 2009; 1 mature male and 2 mature females collected from Tchukulassa, Santa Maria, Sal Island, 25 m, natural substrate, June 2009.

Type locality. Arinaga (N 27º51'52.9'', W 015º23'01.0''), Gran Canaria, Canary Islands, 10 meters deep, seagrass Cymodocea nodosa , November 2011 ( Fig. 1 )

Etymology. The specific name refers to the biogeographical area Macaronesia, which includes the Canary Islands, Azores, Madeira, Salvagen Islands and Cape Verde. Macaronesia derives from the greek makárôn nêsoi, which means cheerful or lucky islands.

Description. Holotype male (vial: MNCN 20.04/9150, slide 1: MNCN 20.04/9151, and slide 2: MNCN 20.04/ 9152) ( Figs. 2–4 ).

Length: 4.5 mm

Lateral view ( Fig. 2 ): Body smooth dorsally. Pereonite 1 fused with head, suture present. Pereonites 2, 3 and 4 with an anterolateral and flattened projection at each side. Pereonites 3–5 subequal in length. Pereonite 7 the shortest.

Gills ( Fig. 2 ): Elongate, length about 3 times width.

Antennae ( Figs. 2 , 3 ): Antenna 1 about 0.4 body length; peduncle setose, article 3 of the peduncle shorter than article 1 and 2; flagellum 8-articulate, article 1 being the result of two fused articles. Antenna 2 with short setae (no swimming setae); basal article of the peduncle with a distal projection; flagellum 2-articulate.

Gnathopods ( Fig. 3 ): Gnathopod 1 basis as long as ischium, merus and carpus combined; propodus length about 2 times width, palm with denticulate margin, with 1 grasping spine; dactylus provided with rows of setulae and distally bifid. Gnathopod 2 inserted on the anterior half of pereonite 2; basis a little longer than pereonite 2, smooth, lacking serrate carina, without distal projection; ischium rectangular; merus rounded; carpus short and triangular; propodus elongate, length about 3 times width; palm with a proximal projection carrying one grasping spine, a medial acute projection, followed by “U” notch and a distal triangular projection, distally denticulate; dactylus elongate, with a round projection medially, minutely denticulate.

Pereopods ( Figs. 2 , 4 ): Pereopods 3 and 4 subequal, 2-articulate, length about 1/5 of gills, proximal article the longest, distal article small provided with 2–3 setae. Pereopod 5 with 2 articles, slightly larger than pereopods 3 and 4, proximal article the longest provided with 3 setae, distal article small provided with 3 setae. Pereopod 6 and 7 with 6 articles; pereopod 7 larger and more robust than pereopod 6, propodus proximally with knobs decreasing in size from proximal to distal end, with strong setae proximally.

Penes ( Fig. 4 ) rounded, situated laterally

Abdomen ( Fig. 4 ) with a pair of appendages 1-articulate and distally serrated, a pair of lateral lobes and a single dorsal lobe, with two plumose setae.

Mouthparts ( Fig. 5 ) figured from the male paratype; (Male 2, vial: MNCN 20.04/9157, slide: MNCN 20.04/ 9158). Mandibles without palp; mandibular molar robust; left mandible with incisor and lacinia mobilis 5-toothed followed by two plates; incisor of right mandible 5-toothed, lacinia mobilis transformed in a plate followed by two more plates; molar flake apparently absent. Upper lip smooth. Lower lip smooth, with round and well-demarcated inner lobes. Maxilla 1 outer lobe with 6 robust setae; palp with 4 distal setae and 1 lateral seta. Maxilla 2 inner lobe triangular; outer lobe slightly larger than inner lobe, rectangular. Maxilliped inner plate small and rectangular with two setae; outer plate about 2.5 times as large as inner plate, with 5 setae; palp 4-articulate, article 3 of the palp with a distal projection, article 4 provided with two seta and tiny branch of setulae distally.

Paratype female (vial: MNCN 20.04/9153, and slide: MNCN 20.04/9154) ( Figs. 2 , 3 , 4 )

Length: 2.7 mm

Similar to the male holotype apart from the following characters: pereonites 3–5 lacking the developed anterolateral projections; flagellum of antenna 1 with 6 articles; pereonite 1 after the suture less elongate than in male; gnathopod 2 propodus more rounded than in male, with a projection proximally with one grasping spines, two smaller projection in the palm and denticulate distally; oostegites on pereonite 3 and 4 with setae; genital openings in the pereonite 5 well-developed; abdomen without appendages, with two lateral lobes and a dorsal lobe.

Intraspecific variation. The morphological characteristics of the species are rather constant in the specimens examined. Mouthparts were similar in the four specimens dissected. The flagellum of antenna 2 was always provided with two articles; the number of articles of antenna 1 flagellum was increasing from 4 (in the smaller juveniles examined) to 8 in the holotype mature male. Insertion of gnathopod 2 was always near proximal end of pereonite 2 regardless of the maturation stage of the specimen ( Fig. 6 ). Length of pereonites 1 and 2 varied according to the stage of development; the distance from the suture to pereonite 2 (pereonite 1 of the cephalon) was increasing from juvenile stages to adult. The smaller juveniles were lacking the anterolateral projections, which develop initially in pereonites 2 and 3 ( Fig. 6 ), and lately in pereonite 4 ( Fig. 2 ). Some juveniles have the pereonite 3 and 4 ventrally expanded ( Fig. 6 ), but in mature males this widening of the body disappear and the pereonites become slender and provided by robust anterolateral and flattened projections ( Fig. 2 ). The morphological variation of male gnathopod 2 is also represented in Fig. 6 . In juveniles the propodus palm lacks projections. In juvenile males, a proximal projection with the grasping spine starts to develop together with a medial projection and “U” notch. The notch is more developed in adult males and the distal triangular projection becomes more evident and denticulate. The medial rounded projection in the dactylus is absent in juveniles and juvenile males. The material collected from Canary Islands is very similar morphologically to the material from Cape Verde and no morphological constant differences could be detected among populations of the two archipelagos.

Ecological remarks. The specimens of Mantacaprella macaronensis were found in Gran Canaria in both types of habitats sampled. It was especially abundant on C. nodosa meadows in Arinaga (10 m depth), showing a mean abundance of 452.5±50.2 ind.m -2, being absent in the locality of Gando 1 (Fig. 7). In Cape Verde, the species was present both in natural rocky and artificial habitats around 25 meters depth, being absent in the areas sampled at 10 m depth (Fig. 7). The maximum mean abundance in Sal Island was found in Kwarcit with an average of 80.0±56.2 ind.m -2.

In Gran Canaria, the amphipod fauna associated with C. nodosa meadows was dominated by Mantacaprella macaronensis , Pseudoprotella phasma and Ampithoe ramondi ; while Microdeutopus stationis, Dexamine spinosa, Aora spinicornis, Ischyrocerus inexpectatus and Apherusa bispinosa were more abundant in C. prolifera - dominated beds. In Sal Island, amphipods were among the most abundant faunal groups, representing, together with polychaetes and sipunculids 80.8% of total abundance. The most abundant amphipod species was Stenothoe sp., however, these organisms were only observed in the artificial reef (Kwarcit). Phtisica marina , Ericthonius sp. and Jassa sp. were also highly abundant and present in both natural and artificial areas.

FIGURE 7. Mean abundance (number of individuals.m -2 ± SE) of the Mantacaprella macaronensis n. sp. on the different studied localities in Gran Canaria and Sal Island. Ven= Veneguera, Ar= Arinaga, RV= Risco Verde, Cab= Cabrón, G1= Gando 1, G2= Gando 2, Tch= Tchukulassa, Far= Farol, Kw= Kwarcit and AS = Santo Antão.

Figures

FIGURE 1. Map of the study area showing the sampling locations in Canary Islands and the Cape Verde. 1: Arinaga (type locality), 2: Risco Verde, 3: Cabrón, 4: Gando 1, 5: Gando 2, 6: Veneguera, 7: Tchukulassa, 8: Farol, 9: Kwarcit and 10: Santo Antão.

FIGURE 2. Mantacaprella macaronensis n. sp. Lateral view of holotype male (4.5 mm) and paratype female (2.7 mm). Scale bar: 1 mm.

FIGURE 3. Mantacaprella macaronensis n. sp. Holotype male antennae, gnathopod 1 and 2. Paratype female gnathopod 2. Scale bars: 0.2 mm. A 1 = Antenna 1; A 2 = Antenna 2; Gn 1 = Gnathopod 1; Gn 2 = Gnathopod 2.

FIGURE 4. Mantacaprella macaronensis n. sp. Holotype male pereopods 3 - 7 and abdomen. Paratype female abdomen. Scale bars: 0.1 mm. P 3 - 7 = Pereopods 3 - 7; Ab = Abdomen.

FIGURE 5. Mantacaprella macaronensis n. sp. Mouthparts of paratype male. Scale bars: 0.05 mm. LL = Lower lip; UL = Upper lip; Mx 1,2 = Maxilla 1,2; LMd = Left mandible; RMd = Right mandible; Mxp = Maxilliped.

FIGURE 6. Mantacaprella macaronensis n. sp. Juvenile stages showing the development of gnathopod 2 and anterolateral projections. Scale bar: 1 mm.