The genera Helicometra Odhner, 1902, Neohelicometra Siddiqi and Cable, 1960, Stenopera Manter, 1933, and Allostenopera Baeva, 1968 are reviewed and the species therein evaluated in consideration of pronounced morphological variations in H. pulchella (Rudolphi, 1819) Odhner, 1902 and other species of these genera. Species possessing a terminal, funnel-shaped oral sucker are transferred to Neohelicometra. Stenopera and Allostenopera are considered invalid. New synonyms include: H. hypodytis Yamaguti, 1934; H. dochmosorchis Manter and Pritchard, 1960; H. aposinuata Pritchard, 1966; H. upapalu Yamaguti, 1970 = H. pulchella; H. neosebastodis Crowcroft, 1947 = H. tenuifolia Woolcock, 1935; H. boseli Nagaty, 1956 = H. equilata (Manter, 1933) Siddiqi and Cable, 1960; H. rectisaccus (Fischthal and Kuntz, 1964) Fischthal and Kuntz, 1965 = H. nasae Nagaty and Abdel Aal, 1962; and H. pugetensis Schell, 1973 = N. pleurogrammi (Baeva, 1968) n. comb. Neohelicometra sebastis n. sp. is described from various species of rockfishes (Sebastes) from the northeastern Pacific. The other species of the genus, Neohelicometra antarcticae (Holloway and Bier, 1968) n. comb; N. pleurogrammi (Baeva, 1968) n. comb.; N. insolita (Polyansky, 1955) n. comb.; and N. scorpaenae Siddiqi and Cable, 1960, possess a cirrus sac which does not extend posterior to the acetabulum, whereas that of N. sebastis normally extends to the miduterine level. A key to the species of Helicometra and Neohelicometra is included.
at 19 oceanographic stations were analyzed for species composition, abundance, biomass and vertical distribution. Sampling was by closing nets hauled vertically at five depth intervals between O and 1900 m. At least 116 species were present in the macro-zooplankton of the study mea. Species not previously reported from the area included the copepods Spinocalanus horridus, Chiridiella reducta, Derjuginia tolli, Neoscolecithrix farrani?, Pachyprilus pacificus, Haloptilus longicirrus?, Mormonillapolaris, and Monstrilla longicirrus?. In addition, small numbers of the previously undescribed adult male stages of the copepods Aetideopsis multiserrata and A. rostrata were found. Three copepod species that appear to be new to science were also collected. The high numbers of species, new records for the area, and previously undescribed species or stages collected reflect the relatively intensive sampling, particularly in deep water. In general, the zooplankton was numerically dominated by copepods, particularly the calanoids Calanus glaciulis, C. hyperboreus, Pseudocalanus minutus, Metridia longa and Microcalanus spp. and the cyclopoid Oithonu similis. Most of these species (exceptions: Metridia longa and Microcalanus spp.) were most abundant in the upper 50 m; total zooplankton numbers were also greatest there. However, one or more stages of each of these copepod species, except P. minutus, were present in depths as great as 1900 m. Factor analysis identified 10 zooplankton assemblages. Of these, two were virtually restricted to the upper 50 m, two were mainly in the upper 50 m but were also found throughout the water column, five were primarily deepwater groups (one almost entirely restricted to deep water), and one was primarily an intermediate depth group.
Over 85% of all ichthyoplankton found in the study area in 1976 and 1978 were young-of-year (Y-O-Y) Boreogadus. Most of the remainder were seasnails (Cyclopteridae). Densities of Y-O-Y cod were related to season, depth, and (to a lesser degree) year and lodation. From June to at least mid-August, Y-O-Y cod were normally most abundant at 10-20 m depth and rare or absent at the immediate surface. Densities decreased below-20 m and no Y-O-Y cod were caught at depths >250 m. After mid-August densities decreased at all depths sampled. More Y-O-Y cod may have been present in the study area in 1976 than in 1978, and Y-O-Y were significantly longer at a given date in 1976 than in 1978.
Incidences and intensities of infection for 19 species of helminths recovered from Sebastes alutus are presented. Seven are regarded as new host records. Lecithophyllum anteroporum Margolis, 1958 is placed in synonymy with L. botryophorum (Olsson, 1868) Odhner, 1905.
Sixty-six specimens of Sebastodes alutus, the Pacific ocean perch, collected from the coast of Oregon and British Columbia were examined for parasitic copepods. The six species identified are Chondracanthus pinguis Wilson, 1912, Chondracanthus triventricosus sp.nov., Clavella parva Wilson, 1912, Brachiella robusta (Wilson 1912) Kabata, 1970, Colobomatus kyphosus sp.nov., and Sarcotaces arcticus Collett 1874. Colobomatus kyphosus is the second species of the genus to be described from the eastern Pacific and Ch. triventricosus is the second chondracanthid to be found in nasal cavities. Sarcotaces arcticus is reported as a parasite of S. alutus for the first time. Details of the appendages of each new species are described and illustrated.
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