Iphinoe tenella Sars, 1878

Mazziotti, Cristina & Lezzi, Marco, 2020, The cumacean genus Iphinoe (Crustacea: Peracarida) from Italian waters and I. daphne n. sp. from the northwestern Adriatic Sea, Mediterranean, Zootaxa 4766 (2), pp. 331-357 : 347-348

Iphinoe tenella Sars, 1878

Iphinoë tenella Sars, 1878: 505 . pl. 15–16; Fage, 1951: 47–49, fig. 40–42.

Iphinoe tenella Bâcescu 1951: 76–77 , fig. 65, 68, 163, 164; Ledoyer 1965: 259–260, pl. 2 fig. 2A, 2B, 3A, 3B, pl. 4 fig. 1A, 1B, pl. 6 fig. 2,3, pl.7 fig. 1, pl. 10 fig. 2,3, pl. 12 fig. 1, pl. 14 fig. 2,3, pl. 16 fig. 1; Jones 1976: 22, fig. 6 K–N. Corbera and García-Rubies 1998: Fig. 4A .

Material examined. 1 adult male, 1 ovigerous female, st. 6; 2 adult males, st. 26; 1 adult male, st. 32; 1 adult male, st. 34; 2 adult males, 1 preparatory male, 10 ovigerous females, 5 subadult females, st 38; 2 ovigerous females, st. 40.

Remarks. Iphinoe tenella is peculiar in that it has six perianal setae on pleonite 6, a trait that is not exhibited by any of the other Mediterranean Iphinoe species, and there is no sternal process in males. It is important to note that the ventral pair of perianal setae are smaller than the median, and the dorsal pair are the biggest. The ventral pair are not easy to observe under a stereoscope. The CL/CD ratio reported by Ledoyer (1968) was 1.84, while the I. tenella specimens that we observed had a larger ratio, reaching an average of 2.34 (2 individuals) at station 40 ( Table 3 ). Iphinoe tenella is a morphologically variable species ( Corbera & Garcia-Rubies1998): some adult males from the Black Sea have an unarmed carapace ( Băcescu 1951; Ledoyer 1965) while Mediterranean and Atlantic populations exhibit serrated carapaces.

Distribution and ecology. Iphinoe tenella has a wide distribution in the Mediterranean Sea. It was recorded from the Alboran Sea (Sánchez Moyano et al. 2001), North-Western basin ( Ledoyer 1968; Corbera & Cardell 1995; Corbera & Garcia-Rubies 1998) and South-Western basin ( Sars 1878, 1879); Central basin ( Valentin 1982; Graeffe 1902), Levantine Sea ( Steuer 1936), and along the Anatolian coast of the Black Sea ( Kirkim et al. 2006; Sezgin et al. 2010). Up to now the known distribution of I. tenella had been confined to areas 1, 3 and 5 of the Bianchi (2004) classification ( Marusso 2006). Here we extend the distribution to sectors 2, 6, 8 and 9 ( Table 3 ). Iphinoe tenella was predominant in muddy bottoms in several localities (i.e. Cacabelos et al. 2010; Kirkim et al. 2006); and in fine sand Kirkim et al. (2006), or over Posidonia oceanica beds and muddy sand at a depth of 10–30 m ( Corbera & Cardell 1995). Our data show that I. tenella occurs on VTC, SVMC, DL, from 5 to 40 m deep.

Figures

FIGURE 4. Sternal process of Iphinoe daphne n. sp. Holotype adult male MZB1008. Scale bars: A: 500 µm; 100 µm.