7,253 research outputs found

    Southern California partyboat sampling study Quarterly Report no. 3

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    During the period January 1 to March 31, 1976, Department personnel made 139 sampling trips aboard southern California partyboats. A total of 22,122 fishes from 73 species was identified and measured. Otoliths were removed from 1,536 rockfish carcasses representing 31 species for use in age determination. Sampling personnel tagged and released 68 California barracuda, Sphyraena argentea, and 18 sablefish, Anoplopoma fimbria. The five most common species sampled during this period represented approximately 79% of the total number of fishes measured. These were, in order of importance; bocaccio, Sebastes paucispinis; chilipepper, Sebastes goodei; olive rockfish, Sebastes serranoides; greenspotted rockfish, Sebastes chlorostictus; and vermilion rockfish, Sebastes miniatus. Bocaccio alone accounted for 52% of the sampled catch. (15pp.

    Southern California independent sport fishing survey Quarterly Report no. 9

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    During the July 1 - September 30, 1977 quarter, 29 launch ramps, hoists, and boat rental locations were sampled 380 times. During the sample days 25,256 anglers and 1,445 divers were interviewed. They expended 179,564 effort-hours and landed 64,371 fishes, molluscs, crustaceans, echinoderms, and coelenterates of 179 identified species. The ten most commonly landed species were 1)white croaker, Genyonemus lineatus, 25%; 2)Pacific mackerel, Scomber japonicus, 8%; 3)olive rockfish, Sebastes serranoides, 7%; 4)kelp bass, Paralabrax clathratus, 6%; 5) blue rockfish, Sebastes mystinus, 3%; 6)barred sand bass, Paralabrax nebulifer, 3%; 7)brown rockfish, Sebastes auriculatus, 2%; 8)spotted sand bass, Paralabrax maculatofasciatus, 2%; 9)grass rockfish, Sebastes rastrelliger, 2%; and 10)queenfish, Seriphus politus, 2%. (28pp.

    Genetic variation of rougheye rockfish (Sebastes aleutianus) and shortraker rockfish (S. borealis) inferred from allozymes

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    Rougheye rockfish (Sebastes aleutianus) and shortraker rockfish (Sebastes borealis) were collected from the Washington coast, the Gulf of Alaska, the southern Bering Sea, and the eastern Kamchatka coast of Russia (areas encompassing most of their geographic distribution) for population genetic analyses. Using starch gel electrophoresis, we analyzed 1027 rougheye rockfish and 615 shortraker rockfish for variation at 29 proteincoding loci. No genetic heterogeneity was found among shortraker rockfish throughout the sampled regions, although shortraker in the Aleutian Islands region, captured at deeper depths, were found to be significantly smaller in size than the shortraker caught in shallower waters from Southeast Alaska. Genetic analysis of the rougheye rockfish revealed two evolutionary lineages that exist in sympatry with little or no gene f low between them. When analyzed as two distinct species, neither lineage exhibited heterogeneity among regions. Sebastes aleutianus seems to inhabit waters throughout the Gulf of Alaska and more southern waters, whereas S. sp. cf. aleutianus inhabits waters throughout the Gulf of Alaska, Aleutian Islands, and Asia. The distribution of the two rougheye rockfish lineages may be related to depth where they are sympatric. The paler color morph, S. aleutianus, is found more abundantly in shallower waters and the darker color morph, Sebastes sp. cf. aleutianus, inhabits deeper waters. Sebastes sp. cf. aleutianus, also exhibited a significantly higher prevalence of two parasites, N. robusta and T. trituba, than did Sebastes aleutianus, in the 2001 samples, indicating a possible difference in habitat and (or) resource use between the two lineages

    Southern California partyboat sampling study Quarterly Report No. 4

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    From 1 April through 30 June, 1976, Department personnel made 146 trips aboard southern California partyboats. A total of 18,218 fishes from 76 species was identified and measured. Otoliths were removed from 674 rockfish carcasses for use in age determination studies. The 10 most common species sampled during this quarter represented 85.2% of the total number of fishes measured. These were, in order of importance: bocaccio, Sebastes paucispinis; kelp bass, Paralabrax clathratus; Pacific bonito, Sarda chiliensis; barred sand bass, Paralabrax nebulifer; chilipepper, Sebastes goodei; California barracuda, Sphyraena argentea; olive rockfish; Sebastes serranoides; white croaker, Genyonemus lineatus; ocean whitefish, Caulolatilus princeps; and vermilion rockfish, Sebastes miniatus. Pacific bonito and California barracuda partyboat landings exceeded those of the entire 1975 season, and sampling data indicate the average length of barracuda caught from partyboats was significantly larger than that of the previous season. (15pp.

    Development of kelp rockfish, Sebastes atrovirens (Jordan and Gilbert 1880), and brown rockfish, S. auriculatus (Girard 1854), from birth to pelagic juvenile stage, with notes on early larval development of black-and-yellow rockfish, S. chrysomelas (Jordan and Gilbert 1880), reared in the laboratory (Pisces: Sebastidae).

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    Larval kelp (Sebastes atrovirens), brown (S. auriculatus), and blackand-yellow (S. chrysomelas) rockfish were reared from known adults, to preflexion stage, nine days after birth for S. chrysomelas, to late postflexion stage for S. atrovirens, and to pelagic juvenile stage for S. auriculatus. Larval S. atrovirens and S. chrysomelas were about 4.6 mm body length (BL) and S. auriculatus about 5.2 mm BL at birth. Both S. atrovirens and S. auriculatus underwent notochord flexion at about 6–9 mm BL. Sebastes atrovirens transform to the pelagic juvenile stage at about 14–16 mm BL and S. auriculatus transformed at ca. 25 mm BL. Early larvae of all three species were characterized by melanistic pigment dorsally on the head, on the gut, on most of the ventral margin of the tail, and in a long series on the dorsal margin of the tail. Larval S. atrovirens and S. auriculatus developed a posterior bar on the tail during the flexion or postflexion stage. In S. atrovirens xanthic pigment resembled the melanistic pattern throughout larval development. Larval S. auriculatus lacked xanthophores except on the head until late preflexion stage, when a pattern much like the melanophore pattern gradually developed. Larval S. chrysomelas had extensive xanthic pigmentation dorsally, but none ventrally, in preflexion stage. All members of the Sebastes subgenus Pteropodus (S. atrovirens, S. auriculatus, S. carnatus, S. caurinus, S. chrysomelas, S. dalli, S. maliger, S. nebulosus, S. rastrelliger) are morphologically similar and all share the basic melanistic pigment pattern described here. Although the three species reared in this study can be distinguished on the basis of xanthic pigmentation, it seems unlikely that it will be possible to reliably identify field-collected larvae to species using traditional morphological and melanistic pigmentation characters. (PDF file contains 36 pages.

    Description of Early Larvae of Four Northern California Species of Rockfishes (Scorpaenidae: Sebastes) from Rearing Studies

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    About 72 species of Sebastes (Family Scorpaenidae) are found along the eastern Pacific coast of North America, some of which are heavily exploited by both commercial and sport fisheries. Because of the large number of species, the identification of early life stages has progressed slowly. The objectives of this study were 1) to rear the larvae of four species of rockfish (Sebastes mystinus, S. carnatus, S. atrovirens, and S. rastrelliger); and 2) to describe the larvae using morphometric measurements, pigmentation patterns, and head spination. Pigmentation was the most useful feature for identification purposes. Two general patterns were found: 1) a short row of ventral midline melanophores on the tail, and none or very little postero-dorsal pigmentation (S. mystinus); and 2) complete ventral midline pigmentation on the tail, and anterior and postero-dorsal melanophores (S. carnatus, S. atrovirens, and S. rastrelliger). With the exception of very early stages of S. carnatus and S. atrovirens, these species can be readily identified. Morphometric proportions and head spination did not show major differences among species. Because of the great similarities found among species in this genus, descriptions from field studies are uncertain to some extent. Laboratory rearings, although difficult, can at least provide early larvae from known species which allow precise identification as well as an estimation ofvariability of characters (e.g., pigmentation) within and between broods.(PDF file contains 22 pages.

    Southern California independent sport fishing survey Quarterly Report no. 10

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    During the October 1 - December 31, 1977 quarter, 28 launch ramps, hoists, and boat rental locations were sampled a total of 294 times. During the sample days 11,942 anglers and 1,025 divers were interviewed. They expended 83,882 effort-hours and landed 36,741 fishes and other organisms of 163 identified species. The ten most commonly landed species were 1) Pacific mackerel, Scomber japonicus, 16%; 2) white croaker, Genyonemus lineatus, 16%; 3) olive rockfish, Sebastes serranoides, 6%; 4) blue rockfish, S. mystinus, 4%; 5) halfmoon, Medialuna californiensis, 4%; 6) Pacific bonito, Sarda chiliensis, 3%; 7) rock scallop, Hinnites multirugosus, 2%; 8) chilipepper, Sebastes goodei, 2%; 9) greenspotted rockfish, S. chlorostictus, 2%; and 10) kelp bass, Paralabrax clathratus, 2%. (25pp.

    Maturity and Fecundity in the Rockfishes, Sebastes spp., a Review

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    Literature was reviewed for data describing fecundity, maturity, and growth in the ovoviviparous genus Sebastes (rockfishes). Assembled data were examined for patterns associated with geographic location and fish length. Rockfishes display great range in length at maturity (9-52 cm total length) and estimated fecundity at maturity (1,700-417,000 eggs or embryos). Within species, length at maturity usually increases at higher latitudes and tends to be greater for females than males. Among species, length at maturity of females is positively and significantly correlated with maximum length and with the ratio of fecundity at maturity to fecundity at maximum length. Fecundity of rockfishes is not notably lower than oviparous fishes such as snappers (Lutjanidae) andcods (Gadidae)

    An ecological analysis of rockfish (Sebastes spp.) assemblages in the North Pacific Ocean along broad-scale environmental gradients

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    Environmental variability affects the distributions of most marine fish species. In this analysis, assemblages of rockfish (Sebastes spp.) species were defined on the basis of similarities in their distributions along environmental gradients. Data from 14 bottom trawl surveys of the Gulf of Alaska and Aleutian Islands (n=6767) were used. Five distinct assemblages of rockfish were defined by geographical position, depth, and temperature. The 180-m and 275-m depth contours were major divisions between assemblages inhabiting the shelf, shelf break, and lower continental slope. Another noticeable division was between species centered in southeastern Alaska and those found in the northern Gulf of Alaska and Aleutian Islands. The use of environmental variables to define the species composition of assemblages is different from the use of traditional methods based on clustering and nonparametric statistics and as such, environmentally based analyses should result in predictable assemblages of species that are useful for ecosystem-based management

    Life history aspects of 19 rockfish species (Scorpaenidae: Sebastes) from the Southern California Bight

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    The authors investigated various life history aspects of 19 rockfish species (Sebastes chlorostictus, S. constellatus, S. dalli, S. elongatus, S. ensifer, S. entomelas, S. flavidus, S. goodei, S. hopkinsi, S. levis, S. melanostomus, S. miniatus, S. ovalis, S. paucispinis, S. rosaceus, S. rosenblatti, S. rufus, s. saxicola, S. semicinctus) from the southern California Bight. These aspects included depth distribution, age-length relationships (of 7 species), length-weight relationships, size at first maturity, spawning season, and fecundity. Growth rates of female S. elongatus, S. hopkinsi, S. ova/is, S. saxicola, and S. semicinctus were higher than male conspecifics. Multiple spawning per season was found in 12 species. Generally, most species spawned between late winter and early summer, though there was some spawning within the genus throughout the year. Spawning season duration ranged from 2 (S. flavidus) to 10 months (S. paucispinis). Spawning seasons tended to start earlier in the year and be of longer duration in the southern California Bight, compared to published data on central California conspecifics. Males matured at a smaller length in 7 of the 17 species studied. Maximum fecundities ranged from 18,000 (S. dalll) to about 2,680,000 (S. levis). (PDF file contains 44 pages.
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