New evidence for solar cycle variations at great distances

Recent studies of solar planetary relationships are directed toward exploring how far out from the sun one could observe solar cycle variations. A positive solar Jovian relationship is suggested from a Chree superposed epoch study of the intensity of the great red spot of Jupiter over a period of about six solar cycles. The characteristic double maxima observed in the solar cycle variation is common to other observations of solar events in the photosphere, chromosphere, and corona; radio and corpuscular emissions from the sun; cosmic ray intensity and geomagnetic activity. The same method of analysis adopted for the study of luminosity changes of the planets Jupiter, Saturn, Uranus, and Neptune indicates that the fluctuations of luminosity follow the single maximum solar cycle represented by sunspot numbers. In conjunction with changes of upper atmospheric density and temperature, it is suggested that the extreme ultraviolet (EUV) emission from the sun may be connected with luminosity changes. A method of distinguishing between phenomena related to solar wind and those related to solar EUV is presented

Observations on the feeding regime of the sea hare aplysia, Donabella rumphi (Cuvier) and its captive spawning and larval rearing trials

Aplysia occurs in a variety of color patterns that correlate with the seaweed upon which it is feeding and living. Aplysia which is a gastropod mollusc is one of the important candidates for marine aquarium. It also has large ganglion nerve cells. This neuron is very similar to those present in vertebrates, making them good subjects for neurological research, electrophysiological studies as well as studies on conditioned responses. At present, we fully depend on exploitation from the wild. In the present contet, spawning of the aplysia Donabella rumphi kept in captivity at Mandapam is reported

Marine ornamental molluscs

The molluscs recorded from the world range from 80,000 to 1,00,000, out of which 50,000 are gastropods, 15,000 bivalves, 500 polyplacophora, 400 cephalopods, 130 aplacophora and 5 monoplacophora. There are 31,463 marine, 8,765 fresh water and 24,503 land molluscs reported from different parts of the world. Humans have valued marine mollusc shells since prehistoric time

Emergence of shore fish traps ‘pattivalai’ - their design and economics of operation along Mandapam coast

Shore fish traps, locally known as ‘‘pattivalai’’ are being operated along the Palk Bay and the Gulf of Mannar coast from Thangachimadam to Pudumadam for a stretch of 35 km. In 1990, there were only a few numbers, which has since increased to more than 30 at present (Fig. 1). This new fishing operation was introduced by Srilankan refugees staying in Mandapam camp

Grading of sacred chanks along Ramanathapuram coast

Fishery of chanks along the Ramanathapuram coast is formed by two varieties viz. Xancus pyrum var acuta (Locally known as Jadhi) and Xancus pyrum var abtusa (Locally known as Patti) under the family Turbinellidae

Recovery of a tagged sacred chank, Xancus pyrum var. acuta Hornell, 1916 (Gastropoda: Turbinellidae) after Six Years

A tagged chank, Xancus pyrum var. acuta was recovered in the Gulf of Mannar off Chinnapalam, six years after release for the first time. It was obtained at 9.5m depth at Chinnapalam in the Gulf of Mannar whereas it was released at 7.0m depth off Kundukal point, Pamban, Gulf of Mannar indicating its restricted movement within the ecosystem. The chank was found to have grown to 30mm in length, 16.8mm in breadth and 305g in weight during the 6 years. The monthly growth rates estimated in terms of shell length (0.41 mm.month-1), maximum shell diameter (0.23 mm.month-1) and total weight (4.17 g. month-1) indicates slow growth. The chank traveled a distance of 11.02 km within 6 years confirming its slow migration