Macropodia rostrata (Linnaeus, 1761)

Spiridonov, Vassily A., Simakova, Ulyana V., Anosov, Sergey E., Zalota, Anna K. & Timofeev, Vitaly A., 2020, Review of Macropodia in the Black Sea supported by molecular barcoding data; with the redescription of the type material, observations on ecology and epibiosis of Macropodia czernjawskii (Brandt, 1880) and notes on other Atlanto-Mediterranean species of Macropodia Leach, 1814 (Crustacea, Decapoda, Inachidae), Zoosystematics and Evolution 96 (2), pp. 609-635 : 609

Macropodia rostrata (Linnaeus, 1761) Fig. 3 a ’’-d’’

Cancer rostratus Linneus, 1761: 493.

Macropodia (Stenorhynchus) rostrata - Pesta, 1918: 318, fig. 9.

Macropodia rostrata - Bouvier 1940: 362, fig. 219; Forest and Zariquiey Álvarez 1964: 225, figs 1, 12; Zariquiey Álvarez 1968: 479, figs 161c, b, 163; Forest 1978: 327, figs 2, 6, 13, 14, 18; Manning and Holthuis 1981: 301-302 (comparison with Macropodia spinulosa ); Ingle and Manning 1982: 272, fig. 1; van Noort and Adema 1985: 364, figs 1-4.; d’Udekem d’Acoz 1999: 201.

Cancer phalangium Pennant, 1777: 8, pl. 9, fig. 17.

Macropodia phalangium - Leach 1815, pl. 23, fig. 6.

Stenorhynchus phalangium - H. Milne Edwards 1834: 279.

Macropodia parva van Noort & Adema, 1985: 371, fig. 12.

? Stenorhynchus inermis Heller, 1856: 3.

Nec Macropodia rostrata - Makarov 2004: 332, figs 161-163 (? = M. czernjawskii )

Material.

North Sea. 6 males, 3 females; North Sea, German Bight; 53°45'N, 37°13'E; SMF 40660.

Mediterranean. 1 female; RV Akademik Kowalevsky, 87th Cruise, Stat 1303; 37°08.00'N, 12°00.70'E; 78 m depth; Sigsbee trawl; 13.09.1978; VV Murina leg; ZMMU Ma4338. 1 male, 1 female, 1 female ov; RV Akademik Kowalevsky, 87th Cruise, Stat 1308; 37°08.9'N, 12°05.2'E, 65 m depth; September 1978; VV Murina leg; ZMMU Ma4336. 1 male; RV Akademik Kowalevsky, 87th Cruise, Stat1316; near Lampeduza, 18.10.1979; VV Murina leg; ZMMU Ma4334. 1 female ov; RV Akademik Kowalevsky, 87th Cruise, Stat 1317(3); 35°28.50'N, 11.0°37.90'E; 72 m depth; 18.09.1979; expedition staff leg; ZMMU Ma3122. 3 males, 2 damaged; RV Akademik Kowalevsky, 90th Cruise, Stat 1396 (2); 37°15'N, 12°08.5'E; 76 m depth, tight sand; 07.09.1980; expedition staff leg; ZMMU Ma4337. 2 males; RV Akademik Kowalevsky, 90th Cruise, Stat 1398 (2); 39°23.60'N, 12°16.50'E, 70 m depth, September 1980; expedition staff leg; ZMMU Ma4335.

Diagnosis.

Cephalothorax, pleon and chelipeds sparsely setose, with significant area smooth. Rostral spines horizontal or slightly ascending in lateral view, usually not reaching the end of 4th article of antennal peduncle, about as long as 8-16% of total carapace length in males and females, with lateral rows of conspicuous curled setae (Fig. 3a' ’’). Epistome with two obtuse lateral protuberances near buccal frame corners (Fig. 3c' ’’). All carapace protuberances, spines and tubercles setose. Gastric region with pair of short lateral protogastric protuberances, without median mesogastric tubercles and obtuse and relatively low median metagastric spine, directed dorsally. Two low hepatic protuberances on each side, lower being more robust. Pterygostomial process visible dorsally in males, but barely in females. Cardiac region elevated, with robust median conical protuberance, directed dorsally or inclined posteriorly. Intestinal region with conspicuous median tubercle (Fig. 3a' ’’, b’’). Basal antennal segment without spines (Fig. 3c' ’’). Merus in pereopods 2-4 with single distal dorsal spine. Dactyli of pereopods 4 and 5 somewhat narrower than propodi, thin, moderately curved, with a dense row of minute to moderate spinules hidden in dense setal band along flexor margin and moderate coverage of longer setae on adductor margin (Fig. 3d' ’’).

Variation.

The specimens from the Mediterranean are all characterised by thin and relatively high gastric and cardiac spines in contrast to relatively low protuberances in the specimens from the North Sea.

Size. (CW). North Sea: females 11.5 mm, female ov 9.5 mm. Males 8.5-11.6 mm. Mediterranean: females 3.7-4.7 mm, females ov 5.0-6.5 mm, males 3.0-6.0 mm.

Ecology.

In the Mediterranean, the species occurs from the upper subtidal zone to about 80 m depth, but usually deeper than 10 m, on a variety of substrates, both soft and hard, including algal and Posidonia oceanica (L.) biotopes ( Zariquiey Álvarez 1968; Pastore 1972; Ingle and Manning 1982; Števćić 1990; d’Udekem d’Acoz 1999; Pipitone and Aculeo 2003; Çelik et al. 2007; Mateo-Ramírez et al. 2016; present study). In the Atlantic, M. rostrata is common and abundant from the intertidal zone to low subtidal zone, primarily on soft bottom, known in seagrass beds (review in d’Udekem d’Acoz 1999) and, in Caulerpa meadows, on sand and clay at 1-3.3 m depth ( López de la Rosa et al. 2006, as Macropodia parva ).

Distribution.

Mediterranean: Western Mediterranean ( Zariquiey Álvarez 1968); Alboran Sea ( García Raso 1984; Mateo-Ramírez et al. 2016); waters around Sicily ( Pipitone and Aculeo 2003); Ionian Sea ( Pastore 1972; Tsagarakis et al. 2013); Adriatic Sea ( Števćić 1990); south-central Mediterranean ( Pipitone and Tumbiolo 1993); Levant Sea (Holthuis and Gotltieb 1958); Dardanelles ( Çelik et al. 2007). North-East Atlantic: from the coast of Iberian Peninsula to North Sea, Shetland Islands and south-eastern Norway (reviewed by d’Udekem d’Acoz 1999).

Remarks.

Macropodia parva , occurring in the North Sea (and reported from some other areas in the Atlantic, i.e. López de la Rosa et al. 2006), is a smaller species than Macropodia rostrata . It may be distinguished by the relative length of antennal segments 3-4 and 5 and the morphology of the dactyli of P 4 and 5. However, these diagnostic characters are subtle and may refer to juveniles of M. rostrata ( d’Udekem d’Acoz 1999). The Mediterranean specimens of M. rostrata , examined by us, show little differences from the North Sea specimens, but have spinules at the inner (flexor) margin of P 5 dactylus nearly over the entire dactylus length, which is the character of M. parva (van Noort and Adema 1985: 378). On the contrary, Manning and Holthuis (1981: 302) found that the dactylus of P 5 in the Mediterranean specimens "has low denticles only on the proximal third". Raupach et al. (2015) found no differences in the sequences of the COI gene in samples of specimens identified as M. rostrata and M. parva from the North Sea. Taking into account morphological variability and molecular genetic data, we regard M. parva as a junior synonym of M. rostrata .

Manning and Holthuis (1981) also suggested that, if the differences between the Atlantic and the Mediterranea specimens of M. rostrata prove to be constant, the Mediterrannean form might deserve a separate status under the name Macropodia inermis (Heller, 1856). However, we have not yet found a substantial support for this view on the basis of morphology. In addition, the genetic markers data for the Mediterranean populations of M. rostrata are lacking. Thus, for the time being, we consider Macropodia inermis (= Stenorhynchus imermis Heller, 1856) as a junior subjective synonym of M. rostrata .

Macropodia rostrata was repeatedly listed for the Black Sea, although, as shown in the introduction, most of these listings could be dated back to Grebnitzky’s (1873) record included in Czerniavsky’s (1884) monograph. This species name continues to “travel” from one regional faunal list to another, up to relatively recent ones (i.e. Gönlügür-Demirci 2006). Kobjakova and Dolgopolskaya (1969) wrote that M. rostrata "occurs in the same places as the other species ( M. longirostris in their concept = M. czernjawskii ) but is, probably a more rarely found species". Although they published an original illustration of M. rostrata ( Kobjakova and Dolgopolskaya 1969: pl. VI, fig. 2), it is not clear from the text if these authors ever had any material from the Black Sea. It was a common practice in the Soviet Union to order professional artists to do illustrations for regional faunistic monographs and manuals. They could use various types of material for drawing, not necessarily originating from the region. If Kobjakova and Dolgopolskaya (1969) had the material of M. rostrata from the Black Sea, it would likely reside in the ZIN-RAS collections, which were apparently used in the process for preparation of their publication. However, it is not the case. We have shown above that it is likely that the " M. rostrata " in Makarov’s (2004) monograph represents M. czernjawskii . Besides this, there are two original records of the species: an old one from Crimea, within a comparative study of decapod fecundity ( Vinogradova 1951); and a recent one from the Turkish coast in the southern Black Sea, within a faunistic-ecological study of Zostera meadows ( Bilgin et al. 2007). In both cases, no details were provided, thus, assuring that these records had not been based on misidentification.

Figures

Figure 3. Comparison of Macropodia czernjawskii (a-d. possible paralectotype, male, ZIN-RAS 88750) to Macropodia tenuirostris (Leach, 1814) (a' - d'. male, SMF 3749) and Macropodia rostrata (Linnaeus, 1761) (a' ' - d' '. SMF 40660). a. Dorsal view. b. Lateral view. c. Anterior part of the body, with antennules, basal antennal segments, and epistome, ventral view. d. Dactylus of pereopod 5. Scale bars: 10 mm (a-a' ' - b-b ''), 1 mm (c-c' ' - d-d '').