Pontocrates marmario, Garcia Gómez & Myers & Avramidi & Grammatiki & Lymperaki & Resaikos & Papatheodoulou & Louca & Xevgenos & Küpper, 2024

Garcia Gómez, Sergio C., Myers, Alan A., Avramidi, Eleni, Grammatiki, Kleopatra, Lymperaki, Myrsini M., Resaikos, Vasilis, Papatheodoulou, Magdalene, Louca, Vasilis, Xevgenos, Dimitrios & Küpper, Frithjof C., 2024, A new species of Pontocrates Boeck, 1871 (Crustacea, Amphipoda, Oedicerotidae) from Cyprus, Zootaxa 5474 (1), pp. 59-67 : 61-65

Pontocrates marmario sp. nov. Garcia Gomez & Myers

( Figures 2–5 )

Type and other materials are in the collection of D100 and D150 respectively on February 08, 2023.

Abbreviations used in figures. Hd = head; C = coxa; G1–2 = gnathopods 1–2; P3–4, P6–7 = pereopods 3–4 and pereopods 6–7; Ep3 = epimeron 3; U1–3 = uropod 1–3.

Type material. Holotype female 3.9 mm, locality name: Dhekelia Bay, south-eastern Mediterranean Sea, sampling station: D100, depth: 3.0 m, collection date: February 08, 2023, collection method: Van Veen grab of surface 0.05 m 2, collectors: Frithjof Küpper, Kleopatra Grammatiki, Myrsini Lymperaki, Vasilis Resaikos, repository: The Natural History Museum of Crete ( NHMC) in Greece, Accession number: [To be provided soon]

Other material. Paratype female (dissected), locality name: Dhekelia Bay, south-eastern Mediterranean Sea, sampling station: D150, depth: 4.8 m, collection date: February 08, 2023, collection method: Van Veen grab of surface 0.05 m 2, collectors: Frithjof Küpper, Kleopatra Grammatiki, Myrsini Lymperaki, Vasilis Resaikos, repository: Biological Research Collection, Department of Biology , University of Aveiro (CoBI-DBUA), Portugal, Accession number: CoBI-DBUA3242.01 .

Etymology. The name used is a combination between Mar (Sea) and Mario with the latter being the name of the son of one of the authors who identified the specimens.

Description (female holotype 3.9 mm) Head. Head rostrum strongly deflected, Antenna 1 flagellum longer than peduncle, with 7 articles, Antenna 2 longer than 1; article 4 and 5 subequal in length; flagellum longer than peduncle with 9 articles.

Pereon. Gnathopod 1 coxa distal margin substraight; basis moderately stout, about 4 x as long as broad, anterior margin substraight; merus with distal extension; propodus subovoid, less than twice as long as broad, palm smooth, oblique, merging imperceptibly with posterior margin and without club-shaped robust setae. Gnathopod 2 coxa subrectangular, anterior and posterior margins substraight; basis elongate, slender; carpus small but with elongate spur that extends beyond tip of propodus; propodus very elongate, slender, chelate, fused throughout its length with the carpus. Pereopod 3 coxa subovoid; basis broad, about 2 x as long as broad, anterior margin substraight, merus anterior margin substraight; carpus and propodus short; propodus a little longer than carpus, subrectangular, distally truncate; carpus and propodus posterior margins with many stout, robust setae; merus and propodus anterodistal margins clothed in very long slender setae; dactylus small. Pereopod 4 similar to pereopod 3 but basis more slender, over than 3 x as long as broad. Pereopod 5 basis anterior margin convex; merus anterodistal margin strongly convex and with exceedingly long setae; carpus short, posterior margin with long setae; propodus longer than carpus, slender, anterior margin with long setae; dactylus elongate, slender. Pereopod 6 basis anterior margin weakly convex; merus anterodistal margin strongly produced into convex lobe overhanging carpus; carpus broad, about twice as long as broad; propodus slender, about twice as long as broad. Pereopod 7 very long, more than half body length, basis subquadriform, distinctly longer than boad the posterior margin straight to weakly concave and with a distinct posterodistal lobe; merus, carpus, propodus and dactylus very long and slender.

Pleon. Epimera 1–3 rounded, with evenly separated long fine marginal setae. Uropods 1–2 slender; peduncles extending about the same length; peduncles longer than subequal rami. Uropod 3 slender; subequal rami longer than peduncle. Telson distally rounded, not incised.

Male unknown.

Habitat. Considering the grain size distribution and statistical ( Blott & Pye 2001) analysis results, the sediment in D100 was characterized as sand and in D150 as slightly gravelly sand following the Folk classification for finegrained sediment ( Folk, 1954). Around the stations D100 and D150, there was mainly hard substrate, however spots of soft substrate were observed around the patches or meadows of seagrass Posidonia oceanica . The study of Xevgenos et al. 2021 as well as the macroscopic observations during diving surveys of May 2022, August 2022, November 2022, and February 2023 demonstrated a very localised impact of the brine discharge on Posidonia oceanica meadows, with the impact reduced markedly at 150 m from the discharge point.At stations D100 and D150, the measurements of physicochemical parameters in bottom seawater and soft benthos do not show a significantly impacted environment from anthropogenic pressures. More specifically, pH and turbidity values for D100 and D150 were within typical range while conductivity values were higher in these stations, i.e., 51.64 mS/cm for D100, 51.94 mS/cm for D 150 in comparison to the value of 41.23 mS/cm in DRef. The concentration of nutrients in water were low as it was expected for the oligotrophic sea of Cyprus. The ratio of organic carbon to Kjeldahl nitrogen (TOC/ TKN) in bottom sediment at both sampling stations was greater than 10 showing anthropogenic influence ( Boehm 1983). Concentration of metals—especially iron, magnesium, and tin—were found to be at similar levels with the reference station. No significant difference in species composition of benthic macroinvertebrates was observed at the sampling stations D100 and D150. Species richness and abundance were low as expected for the oligotrophic condition of the marine environment in Cyprus.

Distribution. Currently known only from the type locality at Dhekelia Bay, Cyprus. More specifically, this taxon was found in the soft benthos samples of the stations D100 (X: 33°45.663’ E, Y: 34°58.768’ N, coordinate system WGS 84, depth: 3.0 m) and D150 (X: 33°45.689’ E, Y: 34°58.785’ N, coordinate system WGS 84, depth: 4.8 m) during the 4th sampling survey conducted in February 2023.

Remarks. In having pereopod 3 and 4 carpus short, gnathopod 1 with a drawn-out meral distal extension and coxa 2 posterior margin straight, P. marmario sp. nov. is closely similar to P. moorei ( Myers & Ashelby 2022) , from the British Isles. It differs in the shape of pereopod 6 that has the anterodistal margin of the merus strongly produced into a convex lobe (weakly produced in P. moorei — Figure 4 ) and the carpus short about twice as long as broad (almost 4 x as long as broad in P. moorei ). It differs from P. moorei also in the basis of pereopod 3 in which the anterior margin is substraight without proximal concavity (sinuous with strong proximal concavity in P. moorei ) and in the basis of pereopod 7 that is longer than broad (almost as broad as long in P. moorei — Figure 4 ).

Figures

FIGURE 2. Pontocrates marmario sp. nov. female 3.9 mm long, Dhekelia Bay, south-eastern Mediterranean Sea, Cyprus.

FIGURE 3. Pontocrates marmario sp. nov. female 3.9 mm, Dhekelia Bay, south-eastern Mediterranean Sea, Cyprus.

FIGURE 4. Pontocrates marmario sp. nov. female 3.9 mm, Dhekelia Bay, south-eastern Mediterranean Sea, Cyprus; x = P. moorei Myers & Ashelby, female, 4.0 mm, Ryde Sands, England.

FIGURE 5. Pontocrates marmario sp. nov. female 3.9 mm, Dhekelia Bay, south-eastern Mediterranean Sea, Cyprus. G2 showing fusion of carpus and propodus; G2 coxa.