Psammechinus miliaris? (Müller, in Knorr, 1771)

Madeira, Patrícia, Kroh, Andreas, Cordeiro, Ricardo, De, António M., Martins, Frias & Ávila, Sérgio P., 2019, The Echinoderm Fauna of the Azores (NE Atlantic Ocean), Zootaxa 4639 (1), pp. 1-231 : 113

Psammechinus miliaris? (Müller, in Knorr, 1771)

Reports for the Azores:

non Echinus microtuberculatus Blainville, 1825 —? $ Barrois 1888: 109 [misidentification];

Psammechinus miliaris ( Gmelin, 1791) — Mortensen 1927a: 294–295; Nobre 1938: 110–111, figs. 48–49;

non Psammechinus microtuberculatus ( Blainville, 1825) — Nobre 1938: 111–112 [based on Barrois 1888]; Tortonese 1965: 333–335, fig. 159 [based on Nobre 1938];? $ Castro & Viegas 1983: 24 [misidentification]; Pereira 1997 [based on Barrois 1888]: 334; Haddad & Barreiros 2008: 9; Micael & Costa 2010: 323 [based on Nobre 1938]; Micael et al. 2012: 4 [based on Barrois 1888];

Psammechinus miliaris (M̹ller, in Knorr, 1771)—? $ Mortensen 1943a: 127–139, figs. 56a–b, 57, 58a–b, 59a, 60b, 63b, pl. 10, figs. 3–5, pl. 18, figs. 1–7, 20–21, pl. 58, figs. 19, 23– 25; Moyse & Tyler 1995: 680, 12.8; Schultz 2006: 198–198, figs. 370–372; Micael & Costa 2010: 323; Micael et al. 2012: 4.

See: Mortensen (1943a); Schultz (2006).

Occurrence: Northeast Atlantic, from Iceland and Scandinavia ( Mortensen 1903) to Cape Blanc ( Mortensen 1925, Nobre 1938), including the?Azores ( Barrois 1888),?Madeira ( Jesus & Abreu 1998),?Canaries and? Cape Verde ( Tortonese 1965).

Depth: 0–100 m ( Mortensen 1927a);? AZO : 10–20 m ( Barrois 1888).

Habitat: virtually any kind of bottom (on bouldery sheltered shores, among sea-grass or algae, under stones, on rocks; Picton 1993); omnivorous, depending on the bottom on which it lives ( Mortensen 1943a).

Larval stage: planktotrophic ( Emlet 1995).

Commercial value: edible (Lawrence, J.M. 2007).

Remarks: Psammechinus microtuberculatus ( Blainville, 1825) was frequently reported from the Azores, unfortunately without descriptions. Koehler (1921b) showed some concerns about the records for the Atlantic, since he believed that the geographical range of this species did not go further than the Iberian Peninsula. Mortensen (1927b, 1943a) stated that the species Psammechinus microtuberculatus was endemic to the Mediterranean Sea and all reports of this species in the NE Atlantic were a result of misidentifications with close related species Psammechinus miliaris or Paracentrotus lividus . Additionally, on reviewing the material collected by Simroth (unreported) Mortensen (1943a) concluded that the animals were far too small (D = 2.5 mm) to allow a reliable identification. Mortensen also added that the material report by Barrois (1888) from the Azores as P. microtuberculatus was presumably lost. We have no knowledge on the whereabouts of Castro & Viegas (1983) material or even if any specimens were actually deposited in a collection. The specimens identified by Marques (1983) as Psammechinus microtuberculatus (housed in the zoological collections of Museu of Bocage–MNHM) proved to be juveniles of Paracentrotus lividus , a common inhabitant of the Azores coastal waters (see remarks under Paracentrotus lividus ). After critically examining the echinoid extant material in the DBUA-ECH collection we could not find a single specimen belonging to either P. microtuberculatus or P. miliaris . In sum, the only known Psammechinus material from the Azores is either lost or too small to allow a reliable identification. Both P. miliaris and P. microtuberculatus species have a planktotrophic larval development with a high dispersal potential ( Emlet 1995). Thus, it is not entirely unlikely that new recruits from the NE Atlantic or even Mediterranean continental coasts could have reached the insular coasts. Furthermore, it is not unprecedented to have Mediterranean species present in the Azores (e.g., the sea star Sclerasterias richardi ). Nevertheless, we follow Mortensen (1943a) in assigning the historical reports of P. microtuberculatus from the Azores to P. miliaris . In the absence of well documented adult specimens, the presence of P. miliaris in the Azores, however, needs to remain doubtful until confirmed by new records.