Hypanis plicata

File:Hypanis plicata Turali.png, Russia).]]

Hypanis plicata has an elongated oval or rounded-trapezoidal, rather thin, compressed, semitranslucent shell, with a low, anteriorly displaced umbo, 30–41 irregularly placed sharp triangular radial ribs, which sometimes bear scales on the anterior margin, and a deep pallial sinus, which extends up to 1/3 of the shell length.{{cite book|last1=Logvinenko|first1=B. M.|last2=Starobogatov|first2=Y. I.|date=1969|chapter=Tip Mollyuski. Mollusca|trans-chapter=Phylum Molluscs. Mollusca|title=Atlas bespozvonochnykh Kaspiyskogo morya|trans-title=Atlas of the Invertebrates of the Caspian Sea|editor-last1=Birshteyn|editor-first1=Y. A.|editor-last2=Vinogradov|editor-first2=L. G.|editor-last3=Kondakov|editor-first3=N. N.|editor-last4=Kuhn|editor-first4=M. S.|editor-last5=Astakhova|editor-first5=T. V.|editor-last6=Romanova|editor-first6=N. N.|location=Moscow|publisher=Pishchevaya Promyshlennost|pages=331–332|language=ru}}{{sfn|Scarlato|Starobogatov|1972|p=216}}{{sfn|Kijashko|2013|pp=386–388}}{{sfn|ter Poorten|2024|p=154}} The shell length is up to {{cvt|30–45|mm}}. The valves are slightly gaping at the anterior and posterior margins. The coloration is white, with thin, semitranslucent light grayish periostracum and sometimes with cream, yellowish or pink bands near the margins.{{sfn|ter Poorten|2024|p=154}} The hinge may have no teeth or a reduced cardinal tooth can be present in the right valve.{{sfn|Scarlato|Starobogatov|1972|p=216}}{{sfn|Kijashko|2013|p=386}}

The siphons of this species are fused together and are longer than its shell when fully extended. The foot is rather short.{{sfn|ter Poorten|2024|p=154}}

Hypanis plicata is widely distributed throughout the Caspian Sea.{{sfn|Kijashko|2013|p=388}} Originally, it was also present in the northwestern Black Sea,{{sfn|Scarlato|Starobogatov|1972|p=216}} where it occurred in the Razelm-Sinoe Lake complex, the Dniester Liman and in the Dnieper-Bug Liman{{cite journal |last1=Gogaladze |first1=A. |last2=Son |first2=M. O. |last3=Lattuada |first3=M. |last4=Anistratenko |first4=V. V. |last5=Syomin |first5=V. L. |last6=Pavel |first6=A. B. |last7=Popa |first7=O. P. |last8=Popa |first8=L. O. |last9=ter Poorten |first9=J. J. |last10=Biesmeijer |first10=J. C. |last11=Raes |first11=N. |last12=Wilke |first12=T. |last13=Sands |first13=A. F. |last14=Trichkova |first14=T. |last15=Hubenov |first15=Z. K. |last16=Vinarski |first16=M. V. |last17=Anistratenko |first17=O. Y. |last18=Alexenko |first18=T. L. |last19=Wesselingh |first19=F. P. |date=2021 |title=Decline of unique Pontocaspian biodiversity in the Black Sea Basin: A review |journal=Ecology and Evolution |volume=11 |issue=19 |pages=12923–12947 |url=https://onlinelibrary.wiley.com/doi/10.1002/ece3.8022 |doi=10.1002/ece3.8022 |doi-access=free|pmid=34646444 |pmc=8495785 |bibcode=2021EcoEv..1112923G |hdl=1887/3238855 |hdl-access=free }} from Nova Odesa to Mykolaiv.{{sfn|Markovsky|1954|p=58}} By the 21st century, however, the Black Sea populations have largely declined due to human activity. The species used to be common in the Razelm-Sinoe Lake complex but disappeared due to rerouting of the Danube and closing of the Black Sea inlets in the second half of the 20th century. The last time H. plicata was seen alive in this locality was in 2004, while a 2007 record{{cite journal |last1=Popa |first1=O. P. |last2=Sárkány-Kiss |first2=A. |last3=Kelemen |first3=B. |last4=Iorgu |first4=E. I. |last5=Murariu |first5=D. |last6=Popa |first6=L. O. |date=2009 |title=Contributions to the knowledge of the present Limnocardiinae fauna (Mollusca: Bivalvia) from Romania |journal=Travaux du Muséum National d'Histoire Naturelle "Grigore Antipa" |volume=52 |pages=7–15}} is a misidentification of Monodacna colorata.{{sfn|ter Poorten|2024|p=142}} The Dniester Liman and the Dnieper-Bug Liman populations have declined due to salinity regime changes and are possibly extinct.

In 2005 several empty valves and a single individual with a damaged soft body were found in the lower Don River near the Porechny Island at a depth of {{cvt|2.5|m}}. These specimens were introduced from the Caspian Sea, but it is uncertain whether the species is able to survive in freshwater conditions of the Don.{{cite journal|last=Nabozhenko|first=M. V.|date=2008|title=Distribution of Mollusks of the Subfamily Lymnocardiinae (Bivalvia, Cardiidae) in the Azov Sea basin|url=https://old.ssc-ras.ru/files/files/78_82_n.pdf|journal=Vestnik. YuNTs RAN|volume=4|number=2|pages=78–82|language=ru}}

In the Caspian Sea Hypanis plicata lives in areas with salinity of at least 4‰ at depths down to {{cvt|30|m}}, less often down to {{cvt|50–70|m}}.{{sfn|Scarlato|Starobogatov|1972|p=216}} In the Dnieper-Bug Liman it was restricted to well-oxygenated silty sediments, where it lived at salinities of 0.7–2‰ at depths from 0.5 to 10 m (1 ft 8 in to 32 ft 10 in) and was abundant and most common at depths of {{cvt|2.0–3.5|m}}.{{sfn|Markovsky|1954|pp=59–60}} The species is a filter feeder that burrows into soft sediments and leaves its long siphons on the surface.{{sfn|Markovsky|1954|p=60}}{{sfn|Kijashko|2013|p=387}} It can also bore deep into hard clay similarly to bivalves of the family Pholadidae.{{sfn|Scarlato|Starobogatov|1972|p=216}}{{sfn|Kijashko|2013|p=387}}{{cite journal|last=Andrusov |first=N. I. |date=1917 |title=Ob obraze zhizni Adacna plicata Eichw.|trans-title=About the lifestyle of Adacna plicata Eichw.|journal=Izvestiya Akademii Nauk |volume=11 |issue=7|pages=457–458|language=ru|url=https://www.mathnet.ru/links/939bd9dbf4d6b9456998a9f5fb1ce78d/im6072.pdf}} Reproduction takes place in the warm period. Fertilization is external and the eggs are released in batches.{{sfn|Kijashko|2013|p=387}}

H. plicata often lives together with bivalves of the genera Dreissena and Adacna.{{sfn|Kijashko|2013|p=387}} In the Razelm-Sinoe Lake complex, the Dniester and Dnieper-Bug limans it have formed relatively species-poor communities together with the cockles Monodacna colorata and Adacna fragilis, but these communities have disappeared by the 21st century due to the severe decline of H. plicata and A. fragilis in these habitats.

Hypanis plicata occurs in the Pleistocene deposits of Azerbaijan, Turkmenistan and the eastern Sea of Azov Region (southern Russia) corresponding to the Apsheronian Basin{{cite book |last=Kolesnikov |first=V. P. |date=1950 |title=Akchagyl'skie i apsheronskie molliuski|trans-title=Akchagylian and Apsheronian molluscs|series=Paleontologija SSSR |volume=10, Chast' 3, Vyp. 12 |location=Moscow; Leningrad |publisher=Izdatel'stvo Akademii nauk SSSR |pages=209–210 |language=ru}}{{cite book |last=Popov |first=G. I. |date=1961 |title=Apsheronskiy yarus Turkmenii|trans-title=The Apsheronian stage of Turkmenia|location=Ashkhabad |publisher=Izdatel'stvo Akademii Nauk Turkmenskoy SSR |pages=276–279 |language=ru}}{{cite journal|last1=Nevesskaja|first1=L. A.|last2=Paramonova|first2=N. P.|last3=Babak|first3=E. V.|date=1997|title=Opredelitel' pliotsenovykh dvustvorchatykh mollyuskov Yugo-Zapadnoy Yevrazii|trans-title=Identification guide to the Pliocene bivalve molluscs of Southwestern Eurasia|journal=Trudy Paleontologicheskogo Instituta|location=Moscow |publisher=Nauka|volume=269|pages=1–267|isbn=5-02-001904-6|language=ru}} which existed on the territory of the modern Caspian Sea from 1,8 or 2,1 million to 880,000–750,000 years ago.{{cite journal|last1=Krijgsman|first1=W.|last2=Tesakov|first2=A.|last3=Yanina|first3=T.|last4=Lazarev|first4=S.|last5=Danukalova|first5=G.|last6=Van Baak|first6=C. G. C.|last7=Agustí|first7=J.|last8=Alçiçek|first8=M. C.|last9=Aliyeva|first9=E.|last10=Bista|first10=D.|last11=Bruch|first11=A.|last12=Büyükmeriç|first12=Y.|last13=Bukhsianidze|first13=M.|last14=Flecker|first14=R.|last15=Frolov|first15=P.|last16=Hoyle|first16=T. M.|last17=Jorissen|first17=E. L.|last18=Kirscher|first18=U.|last19=Koriche|first19=S. A.|last20=Kroonenberg|first20=S. B.|last21=Lordkipanidze|first21=D.|last22=Oms|first22=O.|last23=Rausch|first23=L.|last24=Singarayer|first24=J.|last25=Stoica|first25=M.|last26=van de Velde|first26=S.|last27=Titov|first27=V. V.|last28=Wesselingh|first28=F. P.|date=2019|title=Quaternary time scales for the Pontocaspian domain: Interbasinal connectivity and faunal evolution|url=https://www.sciencedirect.com/science/article/pii/S001282521830415X?via%3Dihub|journal=Earth-Science Reviews|volume=188|pages=1–40|doi=10.1016/j.earscirev.2018.10.013|doi-access=free|hdl=20.500.11937/71421|hdl-access=free}} In the Black Sea Basin the species is known to have occurred since at least the Middle Pleistocene (Chaudian stage of the Black Sea).

Specimens tentatively classified as H. plicata have been found in the Late Pleistocene deposits of the mostly dry Konya Basin in south-eastern Turkey, which was previously occupied by a large lake. In this locality the species is found together with the extinct cockles Monodacna pseudocolorata and Adacna yaninae.{{cite journal|last1=Büyükmeriç|first1=Y.|last2=Wesselingh|first2=F. P.|date=2018|title=New cockles (Bivalvia: Cardiidae: Lymnocardiinae) from Late Pleistocene Lake Karapınar (Turkey): Discovery of a Pontocaspian refuge?|url=https://www.sciencedirect.com/science/article/pii/S1040618215302561|journal=Quaternary International|volume=465|pages=37–45|doi=10.1016/j.quaint.2016.03.018|url-access=subscription}}

The species is considered edible.{{cite book|last1=Ivanov |first1=D. L.|last2=Sysoev |first2=A. V.|date=2009|title=Molluscs in the world cookery |location=Moscow |publisher=KMK Scientific Press Ltd. |page=115 |isbn=978-5-87317-587-1 |language=ru}} The larvae, juveniles and adults are likely eaten by the Caspian roach (Rutilus caspicus), common bream (Abramis brama) and gobies.{{sfn|Kijashko|2013|p=387}} Markovsky (1954) has proposed to introduce H. plicata into reservoirs of large rivers as an additional food source for fish, although it is unknown if its larvae can survive in fresh water.{{sfn|Markovsky|1954|p=60}}

While the conservation status of Hypanis plicata has not been assessed by the International Union for Conservation of Nature,{{cite book|last1=Vinarski|first1=M. V.|last2=Kantor|first2=Y. I.|date=2016|title=Analytical catalogue of fresh and brackish water molluscs of Russia and adjacent countries|location=Moscow|publisher=A. N. Severtsov Institute of Ecology and Evolution of Russian Academy of Sciences|page=73|isbn=978-5-9908840-7-6}} the species has been included in the Red Data Book of Ukraine under the Vulnerable category.{{cite book|last=Munasypova-Motyash|first=I. A.|date=2009|chapter=Hipanis skladchastyy Hypanis plicata (Milashevitch, 1916)|title=Chervona knyha Ukrayiny. Tvarynnyy svit|trans-title=Red Data Book of Ukraine. Animals|editor-last=Akimov|editor-first=I. A.|edition=Third|location=Kyiv|publisher=Globalconsulting|page=307|isbn=978-966-97059-0-7|language=uk}}

File:Glycymeris plicata.jpg

The species was first described as Glycymeris plicata by Karl Eichwald in 1829.{{cite book|last=Eichwald|first=E.|date=1829|title=Zoologia Specialis quam expositis animalibus tum vivis, tum fossilibus potissimum Rossiae in universum, et Poloniae in specie, in usum lectionum publicarum in Universitate Caesarea Vilnensi habendarum. Pars prior. Propaedeuticam Zoologiae atque specialem Heterozoorum expositionem continens|url=https://www.biodiversitylibrary.org/page/35882071|location=Vilnius|publisher=Joseph Zawadzki|page=279|language=la}} The type locality is the southern coast of the Caspian Sea in bight of Astrabad (Gorgan, Iran).{{sfn|ter Poorten|2024|p=154}} The lectotype was selected from a series of possible syntypes which were collected by Eichwald from the type locality and are kept in the Zoological Institute of the Russian Academy of Sciences.{{sfn|Kijashko|2013|p=387}}

The genus Hypanis was introduced in 1832 by Christian Heinrich Pander in a publication by Édouard Ménétries and only included Hypanis plicata,{{cite book|last=Ménétries|first=E.|date=1832|title=Catalogue raisonné des objets de zoologie recueillis dans le voyage au Caucase et jusqu’aux frontières actuelles de la Perse entrepris par ordered s.m. L’Empereur|url=https://www.biodiversitylibrary.org/item/129736|location=St. Petersburg|publisher=Académie Impériale des sciences|page=271|language=fr}} making it the type species of the genus by monotypy.{{cite journal|last1=Vinarski|first1=M. V.|last2=Kijashko|first2=P. V.|last3=Andreeva|first3=S. I.|last4=Sitnikova|first4=T. Y.|last5=Yanina|first5=T. A.|date=2024|title=Atlas and catalogue of the living mollusks of the Aral and Caspian Seas|journal=Vita Malacologica|volume=23|pages=1–124|isbn=978-3-948603-50-2}} Hypanis lacked a diagnosis and only a reference to Eichwald's description of G. plicata was provided.{{sfn|Kijashko|2013|pp=384–385}}

In 1838 Eichwald included G. plicata in the newly described genus Adacna.{{cite journal|last=Eichwald |first=E. |date=1838 |title=Faunae Caspii Maris primitiae |journal=Bulletin de la Société Impériale des Naturalistes de Moscou |volume=11 |number=2|pages=125–174|url=https://www.biodiversitylibrary.org/page/41342125}} Jean Louis Rodolphe Agassiz was possibly unaware of Eichwald's works{{cite journal|last=Andrusov |first=N. |date=1903 |title=Studien über die Brackwassercardiden. Lieferung I.|journal=Zapiski Imperatorskoĭ akademīi nauk, po Fiziko-matematicheskomu otdielenīiu|series=Series 8 |volume=13 |number=3|pages=1–82|language=de|url=https://biodiversitylibrary.org/page/37108785}}{{sfn|Kijashko|2013|p=385}} since he redescribed the species as Pholadomya crispa in 1842.{{cite book|last=Agassiz|first=L.|date=1842|title=Études critiques sur les mollusques fossiles|volume=2|location=Neuchâtel|pages=48–50|url=https://www.biodiversitylibrary.org/page/2016095|language=fr}} Alexander von Middendorff (1849) established the synonymy of Ph. crispa with H. plicata{{cite journal|last=Middendorff |first=A. Th. von |date=1849 |title=Beiträge zu einer Malacozoologia Rossica. III. Aufzählung und Beschreibung der zur Meeresfauna Russlands gehörigen Zweischaler |journal=Mémoires de l'Académie Impériale des Sciences de Saint-Pétersbourg, sixième série, Sciences Naturelles |volume=6 |pages=517–610|url=http://biodiversitylibrary.org/page/29015377|language=de}} but still included the species in Pholadomya.{{sfn|Kijashko|2013|p=385}} Some authors have also placed it in the genera Cardium and Didacna.{{sfn|Kijashko|2013|p=385}} Most researchers retained the species in Adacna, while often also treating Hypanis as its subgenus.{{cite journal|last=Andrusov |first=N. |date=1923 |title=Apsheronskiy yarus|trans-title=Apsheronian Stage|journal=Trudy Geologicheskago Komiteta, novaya seriya |volume=110|pages=1–294|language=ru|url=https://www.molluscabase.org/aphia.php?p=sourceget&id=193888|url-status=live|archive-url=https://web.archive.org/web/20250311090902/https://www.molluscabase.org/aphia.php?p=sourceget&id=193888 |archive-date=11 March 2025}}{{cite book |last=Zhadin |first=V. I. | date=1952 |title=Mollyuski presnykh i solonovatykh vod SSSR |trans-title=Molluscs of Fresh and Brackish Waters of the USSR |url=https://www.zin.ru/publications/fauna_keys/keys_46_zhadin_1952.pdf |series=Opredeliteli po faune SSSR, izdavayemyye Zoologicheskim institutom AN |volume=46 |location=Moscow–Leningrad |publisher=The USSR Academy of Sciences Press |pages=354–355 |language=ru |url-status=live |archive-url=https://web.archive.org/web/20241202230923/https://www.zin.ru/publications/fauna_keys/keys_46_zhadin_1952.pdf |archive-date=2 December 2024}} Nevesskaja (1963) recognized Hypanis as a distinct genus.{{cite journal|last=Nevesskaja|first=L. A.|date=1963 |title=Opredelitel' dvustvorchatykh mollyuskov morskikh chetvertichnykh otlozheniy Chernomorskogo basseyna|trans-title=Key to bivalve molluscs of marine Quaternary sediments of the Black Sea basin |journal=Trudy Paleontologicheskogo Instituta |volume=96|pages=1–211|language=ru}} Logvinenko and Starobogatov (1969) regarded Adacna and Monodacna as subgenera of Hypanis, with H. plicata being included in the subgenus Hypanis s.str. Currently, Adacna and Monodacna are considered to be distinct genera and H. plicata remains to be the only extant member of its genus.{{cite journal|last1=Wesselingh|first1=F. P.|last2=Neubauer|first2=T. A.|last3=Anistratenko|first3=V. V.|last4=Vinarski|first4=M.|last5=Yanina|first5=T.|last6=ter Poorten|first6=J. J.|last7=Kijashko|first7=P.|last8=Albrecht|first8=C.|last9=Anistratenko|first9=O. Y.|last10=D'Hont|first10=A.|last11=Frolov|first11=P.|last12=Gándara|first12=A. M.|last13=Gittenberger|first13=A.|last14=Gogaladze|first14=A.|last15=Karpinsky|first15=M.|last16=Lattuada|first16=M.|last17=Popa|first17=L.|last18=Sands|first18=A. F.|last19=van de Velde|first19=S.|last20=Vandendorpe|first20=J.|last21=Wilke|first21=T.|date=2019|title=Mollusc species from the Pontocaspian region – an expert opinion list|url=https://zookeys.pensoft.net/article/31365|journal=ZooKeys|issue=827|pages=31–124|doi=10.3897/zookeys.827.31365|doi-access=free|pmid=31114425 |pmc=6472301 |bibcode=2019ZooK..827...31W}}

As mentioned above, the name Pholadomya crispa is considered to be a synonym of H. plicata.

File:Adacna relicta Milaschewitsch, 1916.png

Eichwald (1838) classified the Caspian Sea and the Dniester Liman populations of H. plicata as the same species and treated the Dniester population as the variety major. Milaschewitsch (1916) described the Black Sea populations as the species Adacna relicta and indicated that it lives in the Dniester Liman and, possibly, in the Berezan Liman.{{cite book|last=Milaschewitch|first=K. O.|date=1916|title=Mollyuski russkikh morey. Tom 1. Mollyuski Chernago i Azovskago morey|trans-title=Molluscs of the Russian seas. Vol. I. Molluscs of the Black Sea and the Sea of Azov|url=http://www.biodiversitylibrary.org/item/44223|publisher=Imperatorskaya Akademiya Nauk, Zoologicheskiy Muzey|location=Petrograd|series=Faune de la Russie et des pays limitrophes|pages=274–276|language=ru}} Zhadin (1952) regarded A. relicta as a variety of H. plicata, while Nevesskaja (1965){{cite journal|last=Nevesskaja|first=L. A.|date=1965 |title=Pozdnechetvertichnyye dvustvorchatyye mollyuski Chernogo morya, ikh sistematika i ekologiya|trans-title=The Late Quaternary molluscs of the Black Sea, their systematics and ecology |journal=Trudy Paleontologicheskogo Instituta RAS |volume=105|pages=1–390|language=ru}} as well as Scarlato and Starobogatov (1972) recognized it as the subspecies H. plicata relicta.{{sfn|Scarlato|Starobogatov|1972|p=216}} Starobogatov et al. (2004) have once again considered it to be a distinct species, H. relicta,{{cite book|last1=Starobogatov|first1=Y. I.|last2=Bogatov|first2=V. V.|last3=Prozorova|first3=L. A.|last4=Saenko|first4=E. M.|date=2004|chapter=Molluscs|title=Key to Freshwater Invertebrates of Russia and Adjacent Lands|editor-last1=Tsalolikhin|editor-first1=S. J.|volume=6. Molluscs, Polychaetes, Nemerteans|location=Saint-Petersburg|publisher=Nauka|page=48|isbn=5-02-026204-8|language=ru}} but this view was not supported by Kijashko (2013), who retained it as a subspecies since the only distinguishing feature of H. plicata relicta indicated by Nevesskaja (1965) was the deeper pallial sinus.{{sfn|Kijashko|2013|p=386}} Wesselingh et al. (2019) synonymized A. relicta with H. plicata and pointed out that molecular studies would be necessary to clarify the taxonomic status of the Black Sea populations.

File:Adacna plicata 1877.png

Adacna grimmi is a name used by Nicolai Ivanovich Andrusov (1923) to describe a species from the Apsheronian deposits and a modern specimen from the Caspian Sea figured by Oscar Andreevich Grimm (1877).{{cite book|last=Grimm|first=O. A.|date=1877|title=Kaspijskoe more i ego fauna|trans-title=The Caspian Sea and its Fauna |volume=2 (2)|series=Trudy Aralo-Kaspiiskoi Ekspeditsii|location=St. Petersburg|publisher=St. Petersburg Society of Naturalists|page=66|language=ru|url=https://books.google.com/books?id=LikHAQAAIAAJ}} This species was believed to differ from H. plicata by more widely spaced ribs. A. grimmi has been recognized by some subsequent authors, but was synonymized with H. plicata by Logvinenko and Starobogatov (1969).

Borcea (1926) described the variety Adacna relicta var. dolosmiana from the Lake Golovita (Razelm-Sinoe Lake complex) and distinguished it by a less elongated or almost circular shell.{{cite journal|last=Borcea|first=I.|date=1926|title=Quelques remarques sur les Adacnides et principalement sur les Adacnides des Lacs Razelm|trans-title=Some remarks on the Adacnids and mainly on the Adacnids of the Razelm Lakes|url=https://dspace.bcu-iasi.ro/static/web/viewer.html?file=https://dspace.bcu-iasi.ro/bitstream/handle/123456789/478/BCUIASI_PER_X-232%2c%201924-1926%2c%20tome%2013.pdf?sequence=13&isAllowed=y|journal=Annales Scientifiques de l'Université de Jassy|volume=13|issue=3–4|pages=449–473|language=fr}} Scarlato and Starobogatov (1972) treated it as a distinct species, H. dolosmiana.{{sfn|Scarlato|Starobogatov|1972|pp=216–217}} Starobogatov et al. (2004) have proposed that it should be moved to a new genus. Wesselingh et al. (2019) synonymized the variety with H. plicata.

Hypanis plicata golbargae is a subspecies described by Tadjalli-Pour (1977) from Iran.{{cite journal|last=Tadjalli-Pour|first=M. |date=1977 |title=Les Mollusques marins des côtes Iraniennes de la Mer Caspienne (Astara-Hachtpar) |journal=Journal de Conchyliologie |volume=114|number=3–4|pages=87–117|language=fr}} J. J. ter Poorten (2024) regarded it as a synonym of H. plicata.{{sfn|ter Poorten|2024|p=154}}

Hypanis regularis is a name introduced by Starobogatov et al. (2004) which was once again used to describe Grimm's figure of the Caspian H. plicata. Since this specimen was already redescribed by Andrusov in 1923 this makes H. regularis a synonym of A. grimmi, which in turn is a synonym of H. plicata.{{sfn|Kijashko|2013|p=386}}

{{Reflist}}

• {{cite book|last=Kijashko|first=P. V.|date=2013|chapter=Mollyuski Kaspiyskogo morya|trans-chapter=Molluscs of the Caspian sea|title=Identification keys for fish and invertebrates of the Caspian Sea|editor-last1=Bogutskaya|editor-first1=N. G.|editor-last2=Kijashko|editor-first2=P. V.|editor-last3=Naseka|editor-first3=A. M.|editor-last4=Orlova|editor-first4=M. I.|volume=1. Fish and molluscs|location=St. Petersburg; Moscow|publisher=KMK Scientific Press Ltd.|pages=298–392|isbn=978-5-87317-932-9|language=ru}}
• {{cite book|last=Markovsky|first=Y. M.|date=1954|title=Fauna bespozvonochnykh nizov'ev rek Ukrainy, usloviya yeyo sushchestvovaniya i puti ispol'zovaniya. Chast' 2. Dneprovsko-Bugskiy liman|trans-title=The fauna of invertebrates of the lower river streams of Ukraine, its life conditions and ways of utilization. Part 2. The Dnieper-Bug Liman|location=Kyiv|publisher=AN SSSR|language=ru}}
• {{cite book|last=ter Poorten|first=J. J.|date=2024|title=A taxonomic iconography of living Cardiidae|location=Harxheim|publisher=ConchBooks|isbn=978-3-948603-48-9}}
• {{cite book |last1=Scarlato |first1=O. A. |last2=Starobogatov |first2=Y. I. |date=1972 |chapter=Klass dvustvorchatyye mollyuski — Bivalvia |trans-chapter=Class bivalve molluscs – Bivalvia |title=Opredelitel' fauny Chernogo i Azovskogo morey|trans-title=Guide to the fauna of the Black Sea and the Sea of Azov |editor-last1=Mordukhai-Boltovskoy |editor-first1=F. D. |volume=3 |location=Kiev |publisher=Naukova Dumka |pages=178–249 |language=ru}}

{{Taxonbar|from=Q13309404}}

Category:Cardiidae

Category:Molluscs of the Black Sea

Category:Fauna of the Caspian Sea

Category:Bivalves described in 1829

Category:Taxa named by Karl Eichwald