Beroe ovata (Chamisso & Eysenhardt, 1821)

(Fig. 6, Table 3)

? Beroe albens Forskål, 1775 .

? Beroe ovata Bosc, 1802 .

Beroe ovata Chamisso & Eysenhardt, 1821 .

Beroe capensis Chamisso & Eysenhardt, 1821 .

Beroe punctata Chamisso & Eysenhardt, 1821 .

Not Beroe ovata Eschscholtz, 1829 .

Beroe punctata — Eschscholtz, 1829; McCrady, 1859.

Idya mertensii Mertens, 1833 .

Idyiopsis clarkii L. Agassiz, 1860 .

Idyiopsis clarkii — L. Agassiz, 1865.

Idyiopsis affinis L. Agassiz, 1860 .

Beroe ovata — Moser, 1903, 1910; Mayer, 1912 [see for complete synonyms until 1912]; Pratt, 1935; Kremer et al., 1986a; Sterrer, 1986; Mianzan, 1999; Shiganova et al., 2001b.

Beroe capensis — Chun, 1880.

Beroe clarkii Mayer, 1900 .

Not Beroe ovata — Chun, 1880.

Not Beroe “ ovata ” — Mills et al., 1996.

Examined material

22.ix.2003, Near Farol dos Moleques, Canal de São Sebastião, 23°49'27"S 45°24'42"W, A.A.S.Moura coll., one juvenile (ca. 3 mm), reared to 13.x.2003, Fig. 6 J–K, and one adult (ca. 70 mm), fixed in 2% formalin, Fig. 6E (MZUSP00001);

06.iv.2004, Baía do Saco Grande, Canal de São Sebastião, 23°49'35"S 45°25'26"W, bloom of adults (up to 70 mm in length), observed during snorkelling; O.M.P.Oliveira coll., three adults (37–68 mm in length), one specimen preserved in 95% ethanol, other two preserved in 2% formalin (MZUSP00002) ;

05.v.2004, Off Praia do Segredo, Canal de São Sebastião, 23°49'27"S 45°25'19"W, V. Radashevsky coll., two juveniles (ca. 2 mm in length), reared to 11.v.2004, preserved in 2% formalin (MZUSP00003);

21.v.2004, Near Farol dos Moleques, Canal de São Sebastião, 23°49'27"S 45°24'42"W, O.M.P.Oliveira coll., ten adult (10–50 mm in length), reared to 24.v.2004, seven specimens preserved in 2% formalin (MZUSP00004);

18.viii.2004, Off Vila, Ilhabela, Canal de São Sebastião, 23°45'27"S 45°21'49"W, bloom of adults (up to 70 mm in length), observed during snorkelling ;

31.viii.2004, Baía do Saco Grande, Canal de São Sebastião, 23°49'35"S 45°25'26"W, O.M.P.Oliveira coll., one adult (ca. 60 mm in length), reared to 01.ix.2004, preserved in 95% ethanol and two larvae released from reared specimen at 01.ix.2004 (ca. 0.5 mm in length), reared to 02.ix.2004;

27.xi.2004, Baía do Segredo, Canal de São Sebastião, 23°49'27"S 45°25'19"W, O.M.P.Oliveira coll., one adult (ca. 59 mm in length), preserved in 95% ethanol ;

01.iv.2005, Off Praia do Curral, Ilhabela, Canal de São Sebastião, 23°50'54"S 45°25'59"W, one juvenile (ca. 7 mm in length), preserved in 95% ethanol ;

05.iv.2005, Off Praia do Curral, Ilhabela, Canal de São Sebastião, 23°50'54"S 45°25'59"W, ten juveniles (3–12 mm in length), seven specimen preserved in 95% ethanol ;

07.iv.2005, Near Ilha das Cabras, Canal de São Sebastião, 23°49'25"S 45°23'33"W, one juvenile (ca. 8 mm in length), preserved in 95% ethanol ;

17.v.2005, Off Praia do Curral, Ilhabela, Canal de São Sebastião, 23°50'54"S 45°25'59"W, bloom of adults (up to 70 mm in length), observed during snorkelling; O.M.P. Oliveira coll., 39 adults (34–66 mm in length), one specimen measured at 19.v.2005 and reared to 20.v.2005 (table 3, Fig. 6 B–D, MZUSP00005), four specimens reared to 07.vi.2005 (Fig. 6 F–I), 5 specimens preserved in 2% formalin (MZUSP00006), 23 specimens preserved in 95% ethanol .

Description

Flattened body with widened oral extremity, compressed along tentacular plane, reaching about 7.0 cm in length (Fig. 6A,B). Body surface covered by small red spots. Eight meridional canals extending from aboral region to a circular canal around mouth. Canals with lateral diverticula, mostly with blind ends, extending to inner gelatinous portion of body (Fig. 6C). A variable number of diverticula from one meridional canal con­ necting with those of adjacent meridional canal, sometimes forming anastomoses (Fig. 6E). Some diverticula connected with paragastric canals. Rows of ctene plates located above meridional canals, arising at aboral region, extending ca. 3/4 length of meridional canals to oral region. Mouth wide, occupying entire oral region, opening into a large pharynx that occupies most of central inner part of animal. Two opposing paragastric canals extending from aboral pole of pharynx to radial canal around mouth, penetrating jelly beneath diverticula at tentacular plane. Apical organ comprising statolith at centre of polar fields (Fig. 6D). Aboral papillae projecting from margins of polar fields, forming a figure 8 orientated in stomodeal plane. Gonads formed at sides of meridional canals and diverticula (Fig. 6F), testes at distal side and ova at proximal side of canals from tentacular plane in subtentaclar canals and opposite in substomodeal canals. Formation of temporary gonopores through rupture of epidermis near polar fields (Fig. 6G). Gonopore at end of short cone; closing of gonopores leaving no scar on animal surface.

Larva similar to adult, but less compressed along tentacular plane and with no lateral diverticula along meridional canals (Fig. 6K). Body surface covered by conspicuous small red spots (Fig. 6J).

Biological notes

Beroe ovata preys on gelatinous zooplankton, being frequently associated with blooms of Mnemiopsis leidyi and Bolinopsis vitrea . Some authors (e.g. GESAMP 1997, Volovik & Korpakova 2004) believed that this species can be used as a biological­control agent in areas where gelatinous plankton blooms are not desirable, as in the case of the Black and the Caspian Seas (Shiganova et al. 2001b).

The species is supposed to be oviparous, fertilization occurring outside the parental bodies (Carré & Sardet 1984). Indeed, we observed spawning through the temporary gonopores, formed laterally to the apical organ. Male and female gametes were not released at the same time in reared specimens, what would be a way of avoiding self­fertilization outside the parental body. However, we also observed the presence of larvae inside the connected diverticula (Fig. 6 H–I), a strong indication that these larvae were the product of self­fertilization.

We collected and reared in the laboratory for several days specimens in several ontogenetic stages, from 3.0 mm larvae to adults. The smallest specimens were observed eating hydromedusae of about their size.

Remarks

The genus name “ Beroe ” was initially used in the descriptions of ctenophores in general, referring to species that are now within distinct families and genera (e.g. Hormiphora cucumis, Callianira compressa, Euplokamis octoptera, and Dryodora glandiformis, described in Mertens 1833, plates 8–11, as Beroe cucumis, B. compressa, B. octoptera, and B. glandiformis). This wide use of a genus name led to a great confusion around the concept of some species, as “ Beroe ovata ” (cf. Mills et al., 1996, p.161). This species name, with two distinctive origins, currently refers to two biological species (Mills et al. 1996) — “ Beroe ovata ”, described by Chun (1880) and Mayer (1912, as B. cucumis) as having a cylindrical body, and “ Beroe ovata ” (Mayer 1912), with a body compressed along the tentacular axis. Mayer (1912) used other characters, such as the connection between diverticula, to distinguish the species. Recently, in a biomolecular study, Bayha et al. (2004) distinguished two genetic pools of B. ovata: one from the Mediterranean Sea, involving specimens morphologically similar to the ones described by Chun (1880) (= B. cucumis sensu Mayer, 1912), and the other from the North American Atlantic coast and invasive in the Black Sea (= B. ovata as described by Mayer, 1912). Our specimens are closer to those described as B. ovata by Mayer (1912) and Mianzan (1999), except for the patterns of diverticula connections. The range from unconnected to anastomosed diverticula observed by us in specimens of the same population indicates that the anastomosis pattern is not an adequate character to distinguish species of the genus Beroe . Furthermore, an extensive morphological revision, supported by molecular data and including specimens from South Atlantic and Caribbean, should be done to confirm the identity of these nominal species.

Distribution

Species found on coastal waters of the western Atlantic, from USA to Argentina (Mayer 1912, Mianzan 1999). Recently Shiganova et al. (2001b) and Volovik & Korpakova (2004) reported its occurrence in Black and Caspian Seas, as an invader species (cf. Bayha et al. 2004).

Acknowledgments

The authors are grateful to CEBIMar­USP for logistics; to Dr. Hermez Mianzan (INIDEP­ Argentina) and Dr. G. Richard Harbison (WHOI­USA) for providing literature; to Dr. Keith M. Bayha (Dauphin Island Sea Lab­USA) for important suggestions; to Dr. George Matsumoto (MBARI­USA), Dr. Hermez Mianzan (INIDEP­Argentina), and Dr. Steven Haddock (MBARI­USA) for manuscript revisions. License for collecting specimens yielded by IBAMA/MMA (092/2004). Funding was provided by CAPES and FAPESP (Proc. 2004/15300­0) to Otto M. P. Oliveira and CNPq (Proc. 300194 /1994–3) to A. E. Migotto.

References

Agassiz, A. (1865) Illustrated catalogue of the Museum of Comparative Zoology at Harvard College, Vol. 2, North American Acalephae. Sever and Francis, Cambridge, 234 pp.

Agassiz, L. (1860) Contributions to the natural history of the United States of America, Vol. 3. Little, Brown and Co., Boston, 301 pp.

Bayha, K.M.; Harbison, G.R.; McDonald, J.H. & Gaffney, P.M. (2004) Preliminary investigation on the molecular systematics of the invasive ctenophore Beroe ovata. In: Dumont, H.; Shiganova, T.A. & Niermann, U. (Eds.). Aquatic invasions in the Black, Caspian, and Mediterranean Seas. The ctenophores Mnemiopsis leidyi and Beroe in the Ponto­Caspian and other aquatic invasions. NATO Science Series, IV, Earth and Environmental Sciences, Vol. 35. Kluwer Academic Publishers. Dordrecht, Netherlands, p. 167–175.

Bigelow, H.B. (1912) Reports on the scientific results of the expedition to the eastern tropical Pacific, in charge of Alexander Agassiz, by the U.S. Fish Commission Steamer Albatross, from October 1904, to March 1905, Lieutenant Commander L.M. Garrett, U.S.N., commanding. XXVI. The ctenophores. Bulletin of the Museum of Comparative Zoology, 54 (12), 369­408.

Bosc, L.A.G. (1802) Histoire naturelle des Vers. Suite à Buffon 64, Vol. 2, Paris, 300 pp.

Bruguière, J.G. (1789) Encyclopédie méthodique—Histoire naturelle des Vers. Panckouche, Paris. Vol. 16, Part 1, p. 174–177.

Carré, D. & Sardet, C. (1984) Fertilization and early development in Beroe ovata. Developmental Biology, 105, 188–195.

Chamisso, A. & Eysenhardt, C.G. (1821) De Animalibus quibusdam e Classe Vermium Linneana, in Circumnavigatione terrae, auspicante Comite N. Romanzoff, duce Ottone de Kotzebue, annis 1815 –1818. Nova Acta Physico­Medica Acad. Caesareae Leopoldino­Carolinae Naturae Curiosorum, 10 (2), 545–574.

Chun, K. (1879) Die im Golf von Neapel erscheinenden Rippenquallen. Mittelmeer Zoologischen Station von Neapel zugleich repert Mittelmeerkd, 1, 180­217.

Chun, K. (1880) Die ctenophoren des Golfes von Neapel und der angrenzenden Meeres­abschnitte. Fauna and flora des Golfes von Neapel, herausgegeben von der zoologischen Station in Neapel, Vol. 1, Monographie XVIII. Leipzig, 32pp.

Chun, K. (1898) Die Ctenophoren der Plankton Expedition. Ergebnisse der Plankton Expedition der Humboldt­Stiftung, 2, 1–32.

Corrêa, D.D. (1987) Ctenophora. In: Manual de técnicas para a preparação de coleções zoológicas, vol.5. Sociedade Brasileira de Zoologia, Campinas, pp. 1–5.

Delle Chiaje, S. (1841) Animali senza vertebre del Regno di Napoli. Descrizioni e notomia degli animali invertebrati della Sicilia citeriore, osservate vivi negli anni 1822–1830, Vol. 4, Echinodermi, Acalefi, Polipi. Stamperia Societá Tipografica, Napoli.

Dumont, H.; Shiganova, T.A. & Niermann, U. (Eds.). (2004) Aquatic invasions in the Black, Caspian, and Mediterranean Seas. The ctenophores Mnemiopsis leidyi and Beroe in the Ponto­ Caspian and other aquatic invasions. NATO Science Series, IV, Earth and Environmental Sciences, Vol. 35. Kluwer Academic Publishers. Dordrecht, Netherlands, 313 pp.

Eschscholtz, J.F. (1825) Bericht über die zoologische Ausbeute während der Reise von Kronstadt bis St. Peter­ und Paul. Isis, 1, 733–747.

Eschscholtz, J.F. (1829) System der Acalephen. F. Dümmler, Berlin, 190 pp.

Fabricius, O. (1780) Fauna Groenlandica. I. G. Rothe, 452 pp.

Fewkes, J.W. (1881) Studies on the jelly­fishes of Narragansett Bay. Bulletin of the Museum of Comparative Zoology, 8 (8), 141–182.

Fewkes, J.W. (1882) On the Acalephae of the East coast of New­England. Bulletin of the Museum of Comparative Zoology, 9 (8), 291–310.

Fewkes, J.W. (1883) On a few medusa from the Bermudas. Bulletin of the Museum of Comparative Zoology, 11, 79–90.

Fol, H. (1869) Ein Beitrag zur Anatomie und Entwicklungsgeschichte einiger Rippenquallen. Doctoral dissertation, Frierich­Wilhelms University, Berlim.

Forskål, P. (1775) Descriptiones animalium, avium, amphibiorum, piscium, insectorum, vermium; quae in itinere orientali observavit. 164 pp.

Gegenbaur, C. (1856) Studien über Organisation und Systematik der Ctenophoren. Archiv Naturgeschichte, 22 (1), 163–205.

GESAMP (1997) Opportunistic settlers and the problem of the ctenophore Mnemiopsis leidyi invasion in the Black Sea. GESAMP Reports and Studies, No. 58, London, 84pp.

Harbison, G.R. (1985) On the classification and evolution of the Ctenophora. In: Morris, S.C.; George, J.D.; Gibson, R. & Platt, H.M. (eds.), The origin and relationships of lower invertebrates. The Systematic Association, Special Vol. 28, Claredon Press, Oxford, pp. 78–100.

Harbison, G.R. & Madin, L.P. (1979) Diving ­ A New View of Plankton Biology. Oceanus, 22 (2), 18–27.

Harbison, G.R. & Madin, L.P. (1982) Ctenophora. In: Parker, S.P. (Ed.), Synopsis and classification of living organisms. Vol. 1. McGraw­Hill, New York. pp. 707–715.

Harbison, G.R.; Madin, L.P. & Swanberg, N.R. (1978) On the natural history and distribution of oceanic ctenophores. Deep­Sea Research, 25, 233–256.

Harbison, G.R. & Miller, R.L. (1986) Not all ctenophores are hermaphrodites. Studies on the systematics, distribution, sexuality and development of two species of Ocyropsis. Marine Biology, 90, 413–424.

Harbison, G.R. & Volovik, S.P. (1994) The ctenophore, Mnemiopsis leidyi, in the Black Sea: a holoplanktonic organism transported in the ballast of ships. In: Non­Indigenous estuarine & marine organisms (NEMO) and introduced marine species. Proceedings of the Conference and Workshop, NOAA Technological Report, U.S. Department of Commerce. U.S. Government Printing Office, Washington, pp. 25–36.

Ivanov V.P., Kamakin A.M., Ushivtzev V.B., Shiganova T. A., Zhukova O., Aladin N., Wilson S.I, Harbison R and Dumont H.J. (2000) Invasion of the Caspian Sea by the Comb Jellyfish Mnemiopsis leidyi (Ctenophora). Biological Invasions, 2, 255–258.

Jinbiao, Z. (1977) Studies on the Hydromedusae, Siphonophores and Ctenophores from the Coast of the Kiansu and Chekian Province, China. Oceanologia et Technologia Sinica, 7, 95–107.

Kremer, P., Canino, M.F. & Gilmer, R.W. (1986 a) Metabolism of epipelagic tropical ctenophores. Marine Biology, 90, 403–412.

Kremer, P., Reeve, M.R. & Syms, M.A. (1986 b) The nutritional ecology of the ctenophore Bolinopsis vitrea: comparisons with Mnemiopsis mccradyi from the same region. Journal of Plankton Research, 8, 1197–1208.

Krumbach, T. (1925) Erste und einzige Klasse der Acnidaria. Vierte Klasse des Stammes der Coelenterata. Ctenophora. Handbuch der Zoologie, 1, 905­995.

Lesson, R.P. (1843) Histoire naturelle des Zoophytes. Librarie Encyclopèdique de Roret, 596 pp.

Lesueur, M. (1813) Mémoire sur quelques nouvelles espèces d’animaux mollusques et radiaires recueillis dans la Méditerranée, près de Nice. Nouveau Bulletin Société Philomathique, Paris, 3, 281–285.

Marcus, E.B.R. (1956) Vallicula multiformis Rankin, 1956, from Brazil. Boletim do Instituto Oceanográfico, 7 (1– 2), 87–91.

Martindale, M.Q. (2002) Phylum Ctenophora. In: Young, C.M. (Ed.), Atlas of Marine Invertebrate Larvae. Academic Press, San Diego, pp. 109–122.

Matsumoto, G.I. (1988) A new species of lobate ctenophore, Leucothea pulchra sp. nov., from the California Bight. Journal of Plankton Research, 10 (2), 301–311.

Matsumoto, G.I. & Hamner, W.M. (1988) Modes of water manipulation by the lobate ctenophore Leucothea sp. Marine Biology, 97, 551–558.

Matsumoto, G.I. & Harbison, G.R. (1993) In situ observations of foraging, feeding, and escape behavior in three orders of oceanic ctenophores: Lobata, Cestida, and Berioda. Marine Biology, 117, 279–287.

Mayer, A.G. (1900 a) Some medusae from the Tortugas, Florida. Bulletin of the Museum of Comparative Zoology, 37 (2), 13–82.

Mayer, A.G. (1900 b) Descriptions of new and little­known medusae from the western Atlantic. Bulletin of the Museum of Comparative Zoology, 37 (1): 1–9.

Mayer, A.G. (1912) Ctenophores of the Atlantic Coast of North America. Carnegie Institution of Washington (Publ. 162), Washington, 58 pp.

McCrady, J. (1859). Gymnopthalmata of Charleston Harbor. Proceedings of the Elliott Society of Natural History, 1, 103–221.

Mertens, H. (1833) Beobachtungen und Untersuchungen über die beroeartigen Akalephen. Mémoires de L’Académie Impériale des Sciences de St. Pétersbourg (Sixième Série), 2, 479–543.

Mianzan, H.W. (1999) Ctenophora. In: Boltovskoy, D. (Ed.), South Atlantic Zooplankton. Backhuys Publishers, Leiden, pp. 561–573.

Migotto, A.E. & Rodrigues, S.A. (1999) Filo Ctenophora. In: Migotto, A.E. & Tiago. C.G. (Eds.), Biodiversidade do Estado de São Paulo. Síntese do Conhecimento ao final do Século XX, Vol 3. Fundação de Amparo à Pesquisa do Estado de São Paulo, São Paulo, pp. 47–51.

Mills, C.E. (Internet 1998–2005) Phylum Ctenophora: list of all valid species names. Electronic internet document available at http://faculty.washington.edu/cemills/Ctenolist.html. Published by the author, web page established March 1998, last updated April 5, 2005.

Mills, C.E., Pugh, P.R., Harbison, G.R. & Haddock, S.H.D. (1996) Medusae, siphonophores and ctenophores of the Alborán Sea, south western Mediterranean. Scientia Marina, 60(1), 145– 163.

Moser, F. (1903) Die Ctenophoren der Siboga­Expedition. E.J. Brill, Leiden, 34 pp.

Moser, F. (1910) Die Ctenophoren der Deutschen Südpolar­Expedition 1901 –1903. Deutsche Südpolar­Expedition, 11, 117–192.

Müller, O.F. (1776) Zoologiae Danicae Prodromus, seu Animalium Daniae et Norvegiae Indigernarum characteres, nomina, et synonyma imprimis popularium. Copenhagen, Hallager for the author, 282 pp.

Petrechen, M.A. (1946) Ocorrência de Mnemiopsis mccradyi, Mayer 1900 (Ctenophora) no litoral de São Paulo. Anais da Academia Brasileira de Ciências, 18 (2), 117–120.

Pratt, H.S. (1935) A manual of the common invertebrate animals (exclusive the insects). The Blakiston Company, Philadelphia, 854 pp.

Purcell, J.E., Shiganova, T.A., Decker, M.B. & Houde, E.D. (2001) The ctenophore Mnemiopsis in native and exotic habitats: U.S. estuaries versus the Black Sea basin. Hydrobiologia, 451, 145– 176.

Quoy, J.R.C. & Gaimard, J.P. (1824) Zoologie. Deuxième partie. In: Freycinet, L. (Ed.), Voyage autour du Monde, fait par ordre du Roi, sur les corvettes de S.M. D’Uranie et la Physicienne, pendant les annés 1817, 1818, 1819 et 1820. Chez Pillet Ainé, Paris, pp. 409–461.

Ralph, P.M. & Kaberry, C. (1950) New Zealand Coelenterates Ctenophores from Cook Strait. Zoology Publications from Victoria University College, 3, 1–11.

Rang, P.C.A.L. (1828) Établissement de la famille des Béroïdes dans l’ordre des acalèphes libres, et description de deux genres nouveaux qui lui appartiennent. Memories de la Société D’Histoire Naturelle de Paris, 4, 166–173.

Rankin, J.J. (1956) The structure and biology of Vallicula multiformis, gen. et sp. nov., a plactyctenid ctenophore. Journal of the Linnean Society of London, 43, 55­71.

Reeve, M.R. & Walter, M.A. (1978) Nutritional ecology of ctenophores ­ A review of recent research. Advances in Marine Biolology, 15, 249–287.

Seravin, L.N. (1994) The systematics revision of the genus Mnemiopsis (Ctenophora, Lobata). 2. Species attribution of Mnemiopsis from the Black Sea and the species composition of the genus Mnemiopsis. Zoologichesky Zhurnal, 73 (1), 19–34.

Shiganova, T.A., Mirzoyan, Z.A., Studenikina, E.A., Volovik, S.P., Siokou­Frangou, I., Zervoudaki, S., Christou, E.D., Skirta, A.Y. & Dumont, H.J. (2001 a) Population development of the invader ctenophore Mnemiopsis leidyi, in the Black Sea and in other seas of the Mediterranean basin. Marine Biology, 139, 431–445.

Shiganova, T.A., Bulgakova, Y.V., Volovik, S.P., Mirzoyan, Z.A. & Dudkin, S.I. (2001 b) The new invader Beroe ovata Mayer 1912 and its effect on the ecosystem in the northeastern Black Sea. Hydrobiologia, 451, 187–197.

Shiganova, T.A., Christou, E.D., Bulgakova, J.V., Siokou­Frangou, I., Zervoudaki, S. & Siapatis, A. (2004) Distribution and biology of Mnemiopsis leidyi in the Northern Aegean Sea, and comparison with the indigenous Bolinopsis vitrea. In: Dumont, H.; Shiganova, T.A. & Niermann, U. (Eds.). Aquatic invasions in the Black, Caspian, and Mediterranean Seas. The ctenophores Mnemiopsis leidyi and Beroe in the Ponto­Caspian and other aquatic invasions. NATO Science Series, IV, Earth and Environmental Sciences, Vol. 35. Kluwer Academic Publishers. Dordrecht, Netherlands, p. 113­136.

Sterrer, W. (1986) Phylum Ctenophora (Comb­Jellies). In: Sterrer, W. & Schoepfer­Sterrer, C. (Eds.), Marine fauna and flora of Bermuda. A systematic guide to the identification of marine organisms. John Wiley & Sons, New York, pp. 194–197.

Studenikina, Y.I., Volovik, S.P., Mirzoyan, I.A. & Luts, G.I. (1991) The ctenophore Mnemiopsis leidyi in the Sea of Azov. Oceanology, 31 (6), 722–725.

Swanberg, N. (1974) The Feeding Behavior of Beroe ovata. Marine Biology, 24, 69–76.

Volovik, S.P. & Korpakova, I.G. 2004. Introduction of Beroe cf. ovata to the Caspian Sea needed to control Mnemiopsis leidyi. In: Dumont, H.; Shiganova, T.A. & Niermann, U. (Eds.). Aquatic invasions in the Black, Caspian, and Mediterranean Seas. The ctenophores Mnemiopsis leidyi and Beroe in the Ponto­Caspian and other aquatic invasions. NATO Science Series, IV, Earth and Environmental Sciences, Vol. 35. Kluwer Academic Publishers. Dordrecht, Netherlands. p. 177–192.