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INVERTEBRATE ZOOLOGY
ISSN 1812-9250 
ISSN 1814-0815
(online)

 

KMK

 

 

Volume 2, Number 2

New benthopelagic bradfordian calanoids (Crustacea: Copepoda) from the Pacific Ocean with comments on generic relationships

 E.L. Markhaseva 1, Frank D. Ferrari 2

1 Russian Academy of Sciences, Zoological Institute; Universitetskaya nab. 1, 199034, St. Petersburg Russia. e-mail: copepoda@zin.ru

2 Department of Invertebrate Zoology (MRC 534); National Museum of Natural History; Smithsonian Institution; Washington D.C. 20560 U.S.A. e-mail: Ferrari.Frank@MSC.SI.EDU

ABSTRACT: Three new bradfordian genera, and Rythabis heptneri sp.n. and R. schulzi sp.n. are described. Brodskius gen.n. has a narrow mandibular gnathobase with 2 distinct incisions separating groups of teeth, maxilla 1 with 1 long, thick and heavily setulated seta on proximal basal endite and 2 such setae on distal basal endite plus endopod, and setae on the distal basal endite of maxilla 1 inseparable from those of endopod. The new genus includes species formerly known as Amallothrix robustipes Grice, Hulsemann, 1965 and  Xanthocalanus paululus Park, 1970, and B. benthopelagicus sp.n. and B. confusus sp.n., the latter proposed for the paratypes of Xanthocalanus paraincertus Grice, Hulsemann, 1965 which are not conspecific with the holotype. An unnamed male of Brodskius is also described. Xanthocalanus hispidus Grice, Hulsemann, 1967 is not a synonym of B. paululus.

Byrathis gen.n., has the proximal 2 terminal setae on praecoxal endite of maxilla 1 curved proximally, and includes Xanthocalanus macrocephalon Grice, Hulsemann, 1970, B. volcani sp.n., and B. laurenae sp.n.; a poorly-preserved, unnamed female of Byrathis also is described. Omorius gen.n. with the 3rd and 4th setae on the praecoxal endite of maxilla 1 thin and slightly curved is established for Omorius atypicus sp.n. Indistinctly separated groups of setae of the praecoxal endites of the maxilliped is a synapomorphy of Rythabis.

Evolutionary relationships of the new genera to several known bradfordian genera are inferred from an initial loss of one or two setae on the distal praecoxal endite of the maxilliped followed by transformations of sclerotized setae on all praecoxal endites of the maxilliped, and the loss of setae and arthrodial membranes to the exopod of antenna 2. Different pelagic or benthopelagic ancestors to the genera comprising both Phaennidae and Scolecitrichidae suggest these pelagic families are not their own closest relatives. Adaptation to detritivory appears to have resulted in the significant morphological variability of bradfordian calanoid copepods.

KEYWORDS: bradfordian copepods, new species, sensory setae, evolutionary relationships.

(in English with Russian Summary)

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Redescription of Parantipathes euantha (Pasternak, 1958) (Anthozoa: Antipatharia) from Kurile-Kamchatka Trench

 T.N. Molodtsova 1, F.A. Pasternak

1 P.P. Shirshov Institute of Oceanology, Nakhimovsky pr. 36, 117218 Moscow, Russia. e-mail: tina@sio.rssi.ru

ABSTRACT: A redescription of the deep-sea antipatharian Parantipathes euantha (Pasternak, 1958) from the Kurile-Kamchatka Trench is provided. P. euantha differs from the species previously reported in the genus by its less densely set pinnules, which are arranged in semispiral groups of three and by its large polyps up to 2.5–3 mm in transversal diameter. Some details of the microscopical anatomy of P. euantha and also the composition and geographical distribution of the genus Parantipathes Brook, 1889 are discussed. The key for 7 species of the genus Parantipathes is provided.

KEYWORDS: Schizopathidae, Parantipathes, composition of the genus.

(in English with Russian Summary)

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Lumbrineridae (Annelida: Polychaeta) from the Sea of Okhotsk

 N.E. Budaeva

 P.P. Shirshov Instituite of Oceanology, Russian Academy of Sciences, Nakhimovsky Ave., 36, Moscow 117997 Russia. e-mail: nbudaeva@ocean.ru

ABSTRACT: Eleven species of the polychaete family Lumbrineridae Malmgren, 1867 are reported from the Sea of Okhotsk. Ten species belong to four genera: Lumbrineris Blainville, 1828, Errano Kinberg, 1865, Paraninoe Levenstein, 1977 and Scoletoma Blainville, 1828, while one species, Lumbrineridae gen. sp., is of uncertain taxonomic status. Paraninoe abyssalis Imajima et Higuchi, 1975 is reported for the first time for the Russian fauna. Errano sp., Lumbrineris sp. 1, Lumbrineris sp. 2, and Lumbrineridae gen. sp. have never been reported from the Sea of Okhotsk and probably are new species. Lumbrineris heteropoda (Marenzeller, 1879) and Lumbrineris minuta (Théel, 1879) are included in the genus Scoletoma Blainville, 1828. Scoletoma impatiens (Claparède, 1868), Lumbrineris latreilli (Audouin et Milne-Edwards, 1834) and Errano abyssicola (Uschakov, 1950) were previously reported from the Sea of Okhotsk by Ushakov (1955) but not found in the present study.

KEYWORDS: Polychaeta, Lumbrineridae, Sea of Okhotsk, fauna, taxonomy, distribution.

(in Russian with English Summary)

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Astogeny of Cribrilina annulata (Fabricius, 1780) (Bryozoa: Cheilostomata): the standard and the anomalies

 E.B. Yagunova

Department of Invertebrate Zoology, Biology and Soil Science Faculty, St.-Petersburg state university, Universitetskaya nab., 7/9, St.-Petersburg, 199034 Russia. e-mail: katrin.home@mail.ru

 ABSTRACT: About 6000 young colonies of Cribrilina annulata (Fabricius, 1780) were collected from different substrates during consecutive summer seasons of 2000 – 2002s in the White and Barents seas. All colonies have been mapped. After analysing budding pattern, the theoretical morphospace of the structure of early astogenesis zone has been described. Then the number of theoretically possible types of structures has been determined. For the collected colonies the number of realized structures has been counted and, thus, the empirical morphospace of early astogenesis zone has been described as well. It has been demonstrated that only a small part of all theoretically possible colony structures are realized in nature, the proportion of the realized variants decreasing with the increase of the number of zooids in the colony. The frequencies of the discovered structure variants turned out to be considerably different. The astogenesis leading to the most common colony structure has been called the “modal astogenesis”.

The “ideal” astogenesis has been constructed on the assumption of “the perfect precision” of the budding process (synchronized development of all the possible buds). The “ideal” and the “modal” astogenesis have been shown to coincide. So, the diversity of colony structures can be interpreted as a result of fluctuations, accidental deviations from the “ideal” budding mode. This means that the observed plasticity of the colony formity in early development of C. annulata is not adaptive but random. Furthermore, the analysis of the structure variants in collected colonies suggests that the colonies most divergent from the “ideal” ones lack vitality and die.

KEYWORDS: modular construction, astogeny, Bryozoa, Cribrilina annulata.

 (in Russian with English Summary)

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Reproduction and development of the prosobranch gastropod mollusks of Caecidae family in Peter the Great Bay (Sea of Japan)

 K.G. Kolbin 1, V.A. Kulikova

 Institute of Marine Biology, Far-Eastern Branch of the Russian Academy of Sciences, Palchevskogo St., 17, 690041, Vladivostok, Russia. 1e-mail: kolbin_imb@mail.ru

 Abstract: Reproduction and development of the prosobranch gastropod molluscs of Caecidae family, Brochina derjugini Golikov (Golikov et Scarlato, 1967) and Fartulum bucerius Golikov (Golikov et Scarlato, 1967) have been investigated in vitro for the first time. In Vostok Bay (Peter the Great Bay) these species breed in July at 17–20°C water temperature. Both species have internal fertilization, and ontogenesis includes formation of egg masses, from which larvae come out to plankton in the stage of veliger. These two species have similar spawning time, rate of development, morphology of larvae and sculpture of proto- and teleoconch, which indicates their close relationship and allows us to include them to Caecum genus as two subgenera.

KEYWORDS: Caecidae, larvae, egg mass, ontogenesis, protoconch, teleoconch.

 (in Russian with English Summary)

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Feeding of hydromedusae Bougainvillia superciliaris (L. Agassiz, 1849) under experimental conditions (in the White Sea)

 A.A. Prudkovsky

Department of Invertebrate Zoology, Moscow State University, Vorobjevy Gory, Moscow 119992 Russia. e-mail: andand79@mail.ru

ABSTRACT: Medusae are important consumers of zooplankton in the sea. Hydromedusae Bougainvillia superciliaris is a mass form in the White Sea. Their feeding in experimental conditions depends on zooplankton concentration and environment temperature. Digestion time decreases at high temperature: t = 7,4–0,38*T, T — temperature (°Ñ), t — digestion time (h). Ingestion rate of medusae increases at high concentration of prey: lg Rs = 0,44 + 0,62*lg C, Rs — ingest rate (prey/medusae*24 h), C — prey concentration (ind/l). Ingestion rate is highest at concentration of 1000 prey/l. These changes in digestion and ingestion rates  allow B. superciliaris to feed effectively close to the sea surface with abundant but patchily distributed zooplankton.

KEYWORDS: Hydromedusae, Bougainvillia superciliaris, feeding, day ration, zooplankton, White Sea.

(in Russian with English Summary)

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Last updated: Tuesday, 07/08/2014