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| Macropodia czernjawskii (Brandt, 1880) in Spiridonov, Simakova, Anosov, et al., 2020. DOI: 10.3897/zse.96.48342 |
Abstract
Macropodia czernjawskii (Brandt, 1880), described from the Black Sea, was ignored in the regional faunal accounts for more than a century, although it was recognised in the Mediterranean. Instead, M. longirostris (Fabricius, 1775) and M. rostrata (Linnaeus, 1761) were frequently listed for the Black Sea. We selected a lectotype and redescribed the species on the basis of the type series from the Crimean Peninsula and the new material collected in the Black Sea. Historical and new collections, as well as the analysis of publications, indicate that M. czernjawskii is the only Macropodia species occurring in the Black Sea. Molecular barcode (COI gene marker) data show that M. czernjawskii is a species well-diverged from other studied species of the group. Furthermore, M. parva van Noort & Adema, 1985 has very low genetic distances from M. rostrata and M. longipes A. Milne-Edwards & Bouvier, 1899 is indistinguishable from M. tenuirostris (Leach, 1814), using COI sequences. The respective synonimisations, supported by morphological data, are proposed. M. czernjawskii is a Black Sea – Mediterranean endemic occurring also in the neighbouring Atlantic coastal zone of the Iberian Peninsula and occupying shallower depth, compared to other Mediterranean species of Macropodia. As an upper subtidal inshore species, it is particularly specialised in self-decoration and stimulates abundant epibiosis, providing masking and protection. The bulk of epibiosis consists of algae and cyanobacteria. Amongst the 25 autotrophic eukaryote taxa, identified to the lowest possible level, green chlorophytes Cladophora sp. and calcareous rhodophytes Corallinales gen. sp. were most commonly recorded. Non-indigenous red alga Bonnemaisonia hamifera Hariot, first officially recorded at the Caucasian coast of the Black Sea in 2015, was present in the epibiosis of M. czernjawskii in Crimea as early as 2011.
Key Words: Majoidea, historical collections, upper subtidal biotopes, endemism, Mediterranean, egg size, epibiosis, non-indigenous species
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| Figure 5. Macropodia czernjawskii, photographs in natural coloration. a. male (ZMMU Ma 3547), dorsal view. b. Same specimen as a. ventral view. c. female ov (ZMMU Ma 3542), dorsal view. d. Same specimen as c. ventral view. Scale bar: 10 mm. Photographs by SE Anosov. |
Class Malacostraca Latreille, 1802
Order Decapoda Latreille, 1802
Suborder Pleocyemata Burkenroad, 1963
Infraorder Brachyura Linnaeus, 1758
Section Heterotremata Guinot, 1977
Superfamily Majoidea Samouelle, 1819
Family Inachidae MacLeay, 1838
Macropodia czernjawskii (Brandt, 1880)
Diagnosis: Cephalothorax, pleon and thoracopods densely and unevenly setose. Rostral spines covered with large curled setae, moderately ascending, slightly convex to straight in lateral view, somewhat over-reaching (in males), reaching or nearly reaching end of antennal peduncle, usually about as long as 30% of total carapace length in females and about 35% in males. Epistome trapezoidal with two conspicuous lateral spinules on each side. All carapace protuberances, spines and tubercles setose. Gastric region with a pair of lateral protogastric protuberances or spines, a pair of mesogastric tubercles and robust median metagastric spine of moderate height, directed slightly anteriorly or straight dorsally. Two conspicuous hepatic protuberances on each side, lower being most robust. Pterygostomial process seen dorsally in males, but barely in females. Cardiac region elevated, with strong median obtuse spine directed slightly posteriorly. Intestinal region with median spiniform tubercle at border with cardiac region. Basal antennal segment with three (in some specimens two or four) spines. Merus of P 2–5 with a distal dorsal spine. Dactyli of P 4 and 5 little narrower than propodi, markedly curved (sickle-shaped), with a dense row of robust sharp spinules located on flexor margin, along with setae; adductor face with few setae and mostly naked.
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| Figure 10. Natural habitats of Macropodiz czernjawskii in the Black Sea. a, b. Male (ZMMU Ma 3549) in Cystoseira sp., on rock, Tuaphat coastal rock masif, near Gelendzhik. c. Male (ZMMU Ma 3547), on sand, of Blagoveschenskaya village, near Anapa. d. Specimen collected of Blagoveschensakya in aquarium, decorated with red algae after few days of keeping. e. A characteristic biotope of M. czernjawskii in Tuaphat. f. Biotope in Kazachya Cove, Crimean Peninsula where M. czernjawskii has been repeatedly observed. Photographs by SE Anosov. |
Ecology and epibiosis:
In the Black Sea, the species was recorded between 0.5 and 9–12.8 m depth, but mostly within the upper 5–6 m on various substrates from rock and boulders to sand (Fig. 10e, f), in growing or detached aquatic vegetation, i.e. Ulva sp., filamentous green algae, Cystoseira sp., red algae (Fig. 10d). One male was also recorded in a community dominated by clams Chamelea gallina (Linnaeus, 1758), hermit crabs Diogenes pugilator (Roux, 1829) and predatory whelks Rapana venosa (Valenciennes, 1846) at about 10 m depth, where macrophyte vegetation is generally lacking, according to the underwater observations by the authors. It is very difficult to spot the crabs when they are hiding in algae (Fig. 10a). However, the males (but not females) were repeatedly observed walking on bare substrate, although a short distance from shelters and being decorated with pieces of algae (Fig. 10c).
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Vassily A. Spiridonov, Ulyana V. Simakova, Sergey E. Anosov, Anna K. Zalota and Vitaly A. Timofeev. 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): 609-635. DOI: 10.3897/zse.96.48342
