Studies on fish eggs and larvae from Indian waters. 3 Development of egg and early larva of Cypselurus spilopterus (Cuvier and Valencinnes)

The egg embryonic development and early pro-larvae of Cypselurus spilopterus (Cuvier and Valencinnes) are described. Their general appearence is compared with those of the eggs and larvae of other flying fishes reported from this region

Anatomy of a Spin: The Information-Theoretic Structure of Classical Spin Systems

Collective organization in matter plays a significant role in its expressed physical properties. Typically, it is detected via an order parameter, appropriately defined for each given system's observed emergent patterns. Recent developments in information theory, however, suggest quantifying collective organization in a system- and phenomenon-agnostic way: decompose the system's thermodynamic entropy density into a localized entropy, that solely contained in the dynamics at a single location, and a bound entropy, that stored in space as domains, clusters, excitations, or other emergent structures. We compute this decomposition and related quantities explicitly for the nearest-neighbor Ising model on the 1D chain, the Bethe lattice with coordination number k=3, and the 2D square lattice, illustrating its generality and the functional insights it gives near and away from phase transitions. In particular, we consider the roles that different spin motifs play (in cluster bulk, cluster edges, and the like) and how these affect the dependencies between spins.Comment: 12 pages, 8 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/ising_bmu.ht

Characterization of Rhizoctonia solani causing Fruit rot of Strawberry (Fragaria x ananassa Duch.) in Wayanad and in vitro Evaluation of Fungicides, Organic preparations and Bioagents for its Management

Strawberry, one of the most delicate, sweet and refreshing temperate fruit has grabbed the minds of several farmers and consumers all over the world. Several fungal diseases affect it. As part of the study, surveys were carried out in major strawberry growing parts of Kerala viz., Wayanad, Idukki, Malappuram and Thrissur. However, rotten fruits with dark and hard encrustations were collected only from Wayanad district during 2015-16. Pathogen was isolated by following the standard protocol and Koch’s postulates were proved. Upon culturing, the fungal isolate produced white mycelia turning brown on maturation with rapid growth. The hyphae were branched at right angles and did not produce spores. The pathogen was identified as Rhizoctonia solani based on cultural and morphological characters. In vitro evaluation was carried out with 9 fungicides and carbendazim 12% + mancozeb 63% , cymoxanil 8% + mancozeb 64% , propineb and Bordeaux mixture at all concentrations showed cent per cent inhibition. Copper hydroxide and difenoconazole inhibited the pathogen from 54.44 to 75 per cent and 58.88 to 70.55 per cent at 0.1, 0.15 and 0.2 and 0.05, 0.1 and 0.15, respectively. Copper oxychloride recorded less than 45 per cent inhibition, whereas carbendazim and potassium phosphonate were found to be least effective. Comparing the efficacy of organic preparations against Rhizoctonia, calphomil recorded highest inhibition of 55.33 to 63.88 per cent at different concentrations. Panchagavya and baking powder + vegetable oil mixture could inhibit the mycelial growth only by 23.33 to 25.50 per cent and 22.22 to 26 per cent, respectively. Whereas, neem oil was found to be least effective. Biocontrol agents were evaluated against the pathogen and Trichoderma asperellum could restrict growth of the pathogen by 66.67 per cent and Pseudomonas fluorescens by 33.33 per cent

Linkage Between Effective Implementation of IS Strategy and IS Performance: Lessons from Indian Organizations

The overall outcome of IS planning efforts is determined by how effectively the planned strategies are implemented in order to realize the envisaged strategic benefits. This empirical work on IS plan implementation relates the effective implementation of IS plan with IS performance in the Indian context. Based on three case studies from diverse industry segments, we discuss the five important parameters of IS plan implementation- top management commitment, implementation responsibility, IS plan characteristics, user involvement, role of IS function that determine the implementation effectiveness and eventually the IS performance. Based on the analysis, we present a set of key learnings for developing countries, along with implications for future research

An acellular parasite causing mortality of pelagic fish eggs

Planktonic eggs of some pelagic and neritic fishes collected at Madras, Mandapam and Porto Novo were found infected by an acellular parasite, which was found within the yolk of the eggs. The taxonomic identity of the parasite is under investigation. Intense infection was found to lead to the death of eggs as well as the newly hatched larvae. The incidence of infected eggs in the samples was 4% at Madras, 16% at Mandapam and 10.5% at Porto Novo

Studies on fish eggs and larvae from Indian waters I. Development of egg and larvae of Hirundichthys (Hirundichthys) coromandelensis (Hornell)

The developmsnt of Hirundichthys (Hirundichthys) coromandelensis (Hornell) from egg through post-larval stage is described. Results of observations carried out in the laboratory on the hatching of the eggs and the factors affecting the development are discussed. Details of the different stages are given, along with general observations on the spawning and feeding of adults and colouration of the larvae. A brief note on the identification of the species is also appended

Life-history and feeding habits of the spotted seer Scomberomorus guttatus (Block & Schneider)

The available information relating to marine fish eggs and larvae of Madras is covered by the accounts given by John (1951) and Nair (1952 a •+ b). In the present paper, which deals with part of the results of the investigation undertaken by the author at the Zoological Research Laboratory, University of Madras, for three years (1950-53), on fish eggs and larvae occurring in Madras plankton, the methods of collection, of hatching of the eggs and of rearing the larvae in general are given, together with observations on the life-history of Scomberomorus guttdtus vidth its food and feeding habits. Our knowledge of the life history of this fish is confined to Delsman's (1931) description of its eggs and larvae reared up to the third day

Studies on fish eggs and larvae from Indian waters. 2. Development of egg and larvae of Acentrogobius ornatus (Ruppell)

Eggs of Acentrogobius ormtus (Riipp.), attached to Placenta shells were collected along with the parent (male) fish guarding it in knee deep water from the Vellar estuary at Portonovo. The embryonic development from the blastoderm stage up to hatching and the larvae up to the seventh day are described. Besides the present account on A. ornatus, the eggs and early development of its congeners, ^ . n«7/i and/4. v/»-/uncra/«;s have been known. The eggs of<4.ne///j is club shaped and smaller than that of A. ormtus which is stumpy, broader at the base arid is the smallest of all. In A. ormtus o&mA. viridipunctatusths oil globules do not coalesce to form a single one as met with in A. neilli. The egg of y4. ornatus which is the smallest of the three species, has the longest period of incubation. The important features in the embryonic and larval development of the three species are tabulated for comparison

Some observations on the spawning behaviour of mackerel

Past investigations have shown that the Indian mackerel has a prolonged spawning season which extends approximately to four or five months (Devanesan and Chidambaram, 1948; Chidambaram et al, 1952; Bhimachar and George, 1952; Sekharan, 1958). During this period it is believed that the eggs are spawned in a number of successive batches though, so far, there has been no definite proof of it. From the patchiness of distribution of the transparent ova in the ovary Pradhan (1956) had suggested, that only a small percentage of the ova mature each time. Subsequently, more information was brought forth by Sekharan (1958) which indicated the possibihty that the ova are ripened and released in batches. The following is a discussion of the observations on the ovaries of mackerel collected from Portonovo which lend further support to this inference though, however, in regard to certain details Sekharan's observations appear to be somewhat different