Meristic variation in Sebastes (Scorpaenidae), with an analysis of character association and bilateral pattern and their significance in species separation

This report presents meristic data for nearly all of the known species of Sebasles. Rudimentary caudal ray counts tend to be higher in more active species. The number of caudal rays supported by the hypurals is consistently 14, whereas the number of branched caudal rays varies between 11 and 13. Vertebral counts and most fin-ray counts tend to be lower in species or populations in warmer latitudes, except for pectoral ray counts which tend to have an opposite geographic pattern. On the basis of the small magnitude of meristic and morphometric differences and the lack of other differences between northern and southern samples of "Sebasles caurinus," Sebaslichlhys vexillaris Jordan and Gilbert is regarded as a junior synonym of Sebasles caurinus Richardson. The patterns of bilateral variation in paired meristics are analyzed and their mechanism discussed. The frequency distribution of pectoral ray counts in their right-left combination is shown to be useful in species separation. No association was found between any combination of two meristic features in any species. The author proposes that intrasample associations between meristic features are evidence of sampling heterogeneity. (PDF file contains 21 pages.)

Comparison of permanent and temporary streams of calcareous Provence [Translation from: Annales de Limnologie 9(3) 273-292, 1973]

The rainfall regime and the karstic nature of the subsoil determines the alternation of a period of flow and a period of drought for a large number of Mediterranean streams. Amongst this type of stream it is possible to distinguish temporary streams, characterised by a period of flow for several months permitting the establishment of the principal groups of aquatic insects; and ephemeral streams whose very brief period of flow permits the establishment of a community reduced to a few species of Diptera. This paper aims to study the structure of the communities which colonise this particular type of stream and the ecology of the principal species which constitute these communities. Four French temporary streams were examined and temperature regimes, dissolved oxygen, calcium and magnesium measured. Samples of fauna were taken regularly and the biotic composition established. The analysis of similarities between the three permanent streams are discussed and compared with permanent streams.

Physical measures to inhibit planktonic cyanobacteriae

In a small lake, intermittent destratification was installed after several other physico-chemical and physical in-lake therapy measures (phosphorus immobilization, permanent destratification) had been tested without great success. If an aerobic sediment-water interface can be maintained, intermittent destratification removes cyanobacteria and prevents optimal development of other members of the photoautotrophic plankton. During growing seasons, increasing abundances of small-bodied herbivores (Bosmina) and Daphnia may have accounted for relatively low phytoplankton biomass as well. Intermittent destratification is a very fast-working in-lake measure and seems to be applicable even in relatively shallow lakes (< 15 m), in which permanent destratification seems to be risky.

River Lune processes. A study of change in the River Lune catchment and recommendations for flood defence management

There has been a perception of increasing river channel instability in north west rivers and the River Lune in particular in recent decades. This has been attributed variously to: (a) long-term trends in precipitation-runoff regime; (b) changes in land-use such as moor-draining and sub-soil draining such that the river is more flashy than previously, and (c) a change in the magnitude-frequency relationships of flow such that high discharges are occurring with increased frequency. Resources are available in the form of rainfall and runoff records, archived information on channel planform, land use statistics and local engineering experience which have not been jointly and fully evaluated. Effective interpretation of the nature of channel change through time with respect to this resource may enhance the Environment Agency's ability to manage the river channel efficiently in the future and will aid the development of effective policy. The results of this study will for the first time, provide robust guidance with respect to long-term channel adjustment and the appropriate management options. The research provides suggestions as to how policy might be developed taking account of other pertinent factors.

Marine Fisheries Stock Assessment Improvement Plan: report of the National Marine Fisheries Service National Task Force for Improving Fish Stock Assessments

This report argues for greatly increased resources in terms of data collection facilities and staff to collect, process, and analyze the data, and to communicate the results, in order for NMFS to fulfill its mandate to conserve and manage marine resources. In fact, the authors of this report had great difficulty defining the "ideal" situation to which fisheries stock assessments and management should aspire. One of the primary objectives of fisheries management is to develop sustainable harvest policies that minimize the risks of overfishing both target species and associated species. This can be achieved in a wide spectrum of ways, ranging between the following two extremes. The first is to implement only simple management measures with correspondingly simple assessment demands, which will usually mean setting fishing mortality targets at relatively low levels in order to reduce the risk of unknowingly overfishing or driving ecosystems towards undesirable system states. The second is to expand existing data collection and analysis programs to provide an adequate knowledge base that can support higher fishing mortality targets while still ensuring low risk to target and associated species and ecosystems. However, defining "adequate" is difficult, especially when scientists have not even identified all marine species, and information on catches, abundances, and life histories of many target species, and most associated species, is sparse. Increasing calls from the public, stakeholders, and the scientific community to implement ecosystem-based stock assessment and management make it even more difficult to define "adequate," especially when "ecosystem-based management" is itself not well-defined. In attempting to describe the data collection and assessment needs for the latter, the authors took a pragmatic approach, rather than trying to estimate the resources required to develop a knowledge base about the fine-scale detailed distributions, abundances, and associations of all marine species. Thus, the specified resource requirements will not meet the expectations of some stakeholders. In addition, the Stock Assessment Improvement Plan is designed to be complementary to other related plans, and therefore does not duplicate the resource requirements detailed in those plans, except as otherwise noted.

Some aspects of association and development of Lytocestus indicus Moghe in catfish Clarias batrachus (Lin.)

Some aspects of association and development of the caryophyllid cestode Lytocestus indicus Moghe, 1925 infecting the catfish Clarias batrachus (Linn.) from the Kailla Beel of Mymensingh, Bangladesh were studied. About 33.14% of Clarias batrachus were infected with a mean intensity of 3.75, mean density 1.25. The infection was not found throughout the year. Two seasonal occurrence of this cestode were observed, one in April-May and the other in August-September. However, maturation period of the worm coincided with the maturation of the host. The worm was found attached to the wall of the intestine of the host. At the site of attachment tissue layers were compressed due to mechanical injuries. Prevalence and mean intensity of infection increased with length groups. No variation in infection was significantly observed in different sexes of the host examined.

Intertidal transect studies of northern Monterey Bay

In accordance with a contract dated 10/22/71 between the Association of the Monterey Bay Area Governments (AMBAG) and the University of California, Santa Cruz, (UCSC), two permanent intertidal transects with 14 permanent meter-square quadrats were established on the north shore of Monterey Bay during November, 1971. One transect (6 quadrats) was placed on the shore near the Santa Cruz Sanitation outfall, while the second (8 quadrats) was placed near the Eastcliff Sanitation District outfall at Soquel Polnt (Pleasure Point). Animals and plants within the quadrats were listed, their abundance estimated, and representative specimens collected for a reference collection maintained at UCSC. Additional species of animals and plants in the areas of the transects were collected for the reference collection. These collections will serve as a base-line for comparative studies which can follow the magnitude and direction of future changes in these areas.

A record of Probopyrus bithynis (Richardson, 1904) in Macrobrachium rosenbergii (De Man) from coastal Andhra Pradesh, India, with special reference to host-parasite relationship

An incidence of bopyrid isopod infestation was observed in giant freshwater prawn, Macrobrachium rosenbergii (de Man) juveniles (40-60 mm/0.9-1.5 g) in a scampi culture farm in East Godavari district of Andhra Pradesh. The presence of parasite was observed by conspicuous boil like swelling of the branchial chamber where the parasite was found lodged on the gills. The infested gill was highly compressed and necrosed. Only one branchial chamber was infested by the parasite while the other gill was normal. The infested prawns were thin and emaciated and showed retarded growth. The parasite was identified as Probopyrus bithynis (Richardson, 1904) which caused inhibition of ventilation due to its permanent lodging in the branchial chamber and impaired the gaseous exchange by gills. It was also observed that this parasite caused parasitic castration in the infested prawns.

First record of a spindle cowry Crenovolva (Ovulidae, Gastropoda) from Bulleji, Karachi, on the gorgonian coral Muricella sp. and with a note on their association

Attached to hard substrata on our shores occur the branching colonies of gorgonian corals of the genus Muricella (Fig. 1A, Pl. 1B, C, D). Since there is no report on this genus from Pakistan this report be taken as the first record from here. The family Ovulidae comprises several hundred species of marine gastropods, all of which appear to be obligate associates of cnidarians as stated by Robertson (1970) and Hadfield (1976); the present ovulid gastropod genus Crenovolva lives exclusively on the gorgonians (Morton, 1989). Tirmizi and Zehra (1984) recorded thirty-two families of gastropods from Pakistan, but not any representative of the Ovulidae, so the material at hand may be the first record from Pakistan. Since we are unable to reach to specific level the material is being reported as unspecified.