Obata I., Futakami M., Suzuki T., 1991: Eubostrychoceras densicostatum Matsumoto, a large Heteromorph ammonite species, from the Upper Cretaceous of Wakkanai in Hokkaido. 7 pp. Memoirs of the National Science Museum 24: 27-33.

 Ocana A., Brito A., Nunez J., 1992: A new species of Sarcodictyon (Anthozoa: Stolonifera) from Tenerife, Canry Islands. 6 pp. 

 Ocana A., Brito A., Nunez J., 1992: A new species of Sarcodictyon (Anthozoa: Stolonifera) from Tenerife, Canry Islands. 6 pp. [EVE 543] Zoologische Mededelingen 66(31): 423-428.

 Ocana A., Hernández J. A., Monterrubio E., 1999: Description of Achromadora gracilis n. sp. and observations on A. micoletzkyi (Stefanski, 1915) Van der Linde, 1938 and Ethmolaimus multipapillatus Paramonov, 1926 (Nematoda: Chromadorida) from Spanish lakes. 12 pp. 

 Ocana A., Hernández J. A., Monterrubio E., 1999: Description of Achromadora gracilis n. sp. and observations on A. micoletzkyi (Stefanski, 1915) Van der Linde, 1938 and Ethmolaimus multipapillatus Paramonov, 1926 (Nematoda: Chromadorida) from Spanish lakes. 12 pp. [EVE 544] Zoologica Baetica 10: 3-14.

 Ocana A., Sanchéz Tocino L., 2005: Spawning of Holothuria tubulosa (Holothurioidea, Echinodermata) in the Alboran sea (Mediterranean Sea). 4 pp. Zoologica Baetica 16: 147-150.

 Ocana A., Sanchéz Tocino L., San Martín G., 2005: Description of egg masses of three species of sedentary polychaetes of the Mediterranean sea. 5 pp. Zoologica Baetica 16: 165-169.

 Ocana A., Tocino L. S., López-Gonzáles P. J., 2001: Faunistic and biogeographical observations concerning the Anthozoa (Cnidaria: Anthozoa) of the Granada coast (Sea of Alboran). 9 pp. [EVE 545] [80114] Zoologica Baetica 11(2000): 51-65.

 Odier F., Vago C., Lamy M. E., 1974: Persistence of virus of vertebrates in the hemocoel of insects: Study on the Poliovirus into the larvae of Coleoptera. 7 pp. (in French). [EVE 948] [COL 1664]  Annales de la Societe entomologique de France (N.S.) 10(2): 449-455.

 Ofwegen L. P. van, 1989: On Wrightella coccinea (Ellis & Solander, 1786) and Wrightella stiasnyi spec. nov. (Anthozoa: Gorgonacea: Melithaeidae). 8 pp. Zoologische Mededelingen Leiden 63(3): 27-34.

 Ofwegen L. P. van, 1990: Notes on the Keroeididae (Anthozoa: Gorgonacea) collected in 1963 and 1964 by the international Indian ocean expedition of the r/v “Anton Bruun”, in the Indian ocean, with the description of a new species, Lignella hartogi. 6 pp. Zoologische Mededelingen Leiden 63(13): 163-168.

 Ofwegen L. P. van, 2005: A new genus of nephtheid soft corals (Octocorallia: Alcyonacea: Nephtheidae) from the Indo-Pacific. 236 pp. Zoologische Mededelingen Leiden 79(4): 1-236.

 Ofwegen L. P. van, 2008: The genus Sinularia (Octocorallia: Alcyonacea) at Palau, Micronesia. 105 pp. Zoologische Mededelingen 82: 631-735.

 Ofwegen L. P. van, 2008: The genus Sinularia (Octocorallia: Alcyonacea) from Bremer and West Woody islands (Gulf of Carpentaria, Australia). 35 pp. Zoologische Mededelingen 82: 131-165.

 Ofwegen L. P. van, Alderslade P., 2007: A new species of Alertigorgia (Coelenterata: Octocorallia: Anthothelidae) from the Indo Malayan region. 8 pp. Zoologische Mededelingen Leiden 81: 241-249.

 Ofwegen L. P. van, Benayahu Y., 1992: Notes on Alcyonacea (Octocorallia) from Tanzania. 16 pp. 

 Ofwegen L. P. van, Benayahu Y., 1992: Notes on Alcyonacea (Octocorallia) from Tanzania. 16 pp. [EVE 546] Zoologische Mededelingen 66(6): 139-154.

 Ofwegen L. P. van, Hermanlimianto M. I. Y. T., 2014: Siboga plexaurids (Coelenterata: Octocorallia) re-examined. 40 pp. Zoologische Mededelingen 88(1-4): 19-58.

 Ofwegen L. P. van, Vennam J., 1991: Notes on Octocorallia from the Laccadives (SW India). 12 pp. 

 Ofwegen L. P. van, Vennam J., 1991: Notes on Octocorallia from the Laccadives (SW India). 12 pp. [EVE 547] Zoologische Mededelingen 65(9): 143-154.

 Ofwegen L. P. van, Vennam J., 1994: Results of the Rumphius biohistorical expedition to Ambon (1990). Part 3. The Alcyoniidae (Octocorallia: Alcyonacea). 24 pp. 

 Omori M., Vervoort W., 1986: Observations on a living specimen of the giant hydroid branchiocerianthus imperator. 5 pp. Zoologische Mededelingen 60(16): 257-261.

 Opravilová V., Vaňhara J., Sukop I., 1999: Aquatic invertebrates of the Pálava Biosphere Reserve of UNESCO. 279 pp.  Discount 20%!

 Opresko D. M., 2001: Revision of the Antipatharia (Cnidaria: Anthozoa). Part I. Establishment of a new family, Myriopathidae. 28 pp. Zoologische Mededelingen Leiden 75(17): 343-370.

 Opresko D. M., 2004: Revision of the Antipatharia (Cnidaria: Anthozoa). Part IV. Establishment of a new family, Aphanipathidae. 31 pp. Zoologische Mededelingen Leiden 78: 209-240.

 Opresko D. M., 2005: New genera and species of antipatharian corals (Cnidaria: Anthozoa) from the North Pacific. 37 pp. Zoologische Mededelingen Leiden 79 (2): 129-165.

 Opresko D. M., 2006: Revision of the Antipatharia (Cnidaria: Anthozoa). Part V. Establishment of a new family, Stylopathidae. 30 pp.  Zoologische Medelingen 80(4): 109-138.

 Opyrchalowa J., Sadkowska H., 1962: Wystepowanie kedzierzawki plaszczyncowej – Beta virus 3 (Wille) Smith oraz zóltaczki wirusowej – Beta virus 4 (Roland et Quanjer) Smith na burakach cukrowych, jako wskaznik pojawu plaszczynca burakowego – Piesma quadrata Fieb., i mszycy burakowej – Aphis fabae Scop., w województwie wroclawskim w r. 1961. 11 pp. 

 Ortega I., Díaz Y. J., Martín A., 2010: Feeding rates and food preferences of the amphipods present on macroalgae Ulva sp. and Padina sp. Tasas de alimentación y preferencias alimenticias de los anfípodos presentes en las algas Ulva sp. y Padina sp. 9 pp. Zoologica Baetica 21: 45-53.

 Oshiro L. M. Y., 1999: Aspectos reprodutivos do caranguejo guaia, Menippe nodifrons Stimpson (Crustacea, Decapoda, Xanthidae) da Baía de Sepetiba, Rio de Janeiro, Brasil. 8 pp. Revta bras. Zool. 16(3): 827-834.

 Ossiannilsson F., 1966: Making permanent fluid mounts of minute arthropods. 5 pp. (in English). Entomologisk Tidskrift 87(1-2): 1-4.