Feeding and reproductive biology of Saurida undosquamis (Richardson, 1848) from Parangipettai coast, Southeast coast of India.
The feeding biology, spawning season, size at first maturity, sex ratio and fecundity of the commercially important lizardfish (Saurida undosquamis) were studied in Parangipettai waters of the southeast coast of India. Fishes formed the predominant food item. Diversity of the prey items showed maximum value (H'log 2-3.61 +/- 0.11) during the postmonsoon season and minimum during the monsoon season (2.89 +/- 0.17). The richness (1-lambda') also showed a similar trend and varied from 0.81 +/- 0.13 (monsoon) to 0.91 +/- 0.01 (postmonsoon). The size at first maturity (50% incidence of mature fish) was 195 mm. But when the size at first maturity was calculated by adjusting the proportion of maturity percentages, the maturity size was found to be 140 mm. This method is advantageous from the point of view of fisheries management as this species can be exploited above 140 mm rather than above 195 mm. The gastrosomatic index was found maximum during postmonsoon and minimum during the monsoon season showing the inverse relationship between feeding and spawning. This species was found to spawn from August to January with a peak in November. The fecundity ranged from 19, 856 in a fish measuring from 20.1 cm in length (97 g) to 79,282 in a fish of 29 cm (290 g). The overall sex ratio (1:1.19) was found to deviate significantly from the expected 1:1 ratio. (chi2 = 19.1, p < 0.005). Month- wise, it conformed to the expected 1:1 ratio during most of the months except January, June, September, November and December. Higher gonado-somatic index values observed during October-December suggested spawning activity during this period. This species is found to a total spawner in the Parangipettai waters.
Food And Feeding Habits of Two Major Lizardfishes (Family: Synodontidae) Occurring along North-West Coast of India Between Lat. 18°-23°N
Lizardfishes are commercially important group of species contributing to the fishery in the Indian EEZ. Information on predation, prey-predator relationship and their assessments in respect of Saurida tumbil and Saurida undosquamis have been derived in this study. A total number of 1630 specimens of S. tumbil and 926 of S. undosquamis were used for stomach content analysis. The specimens of S. tumbil examined in the study ranged between 13.0-53.0 cm (TL) and of S. undosquamis 13.0-41.0 cm. Qualitative and quantitative analysis revealed that the species S. tumbil prefers food in order of abundance as a teleost fishes (41%), molluscs (9.16%), shrimps (3.64%), crabs (1.41%) and squilla (0.37%) and S. undosquamis prefers teleost fishes (49%), molluscs (11%) and shrimps (3%). In S. tumbil, the highest feeding intensity observed in July (50%) and in S. undosquamis, in October (41%) and the lowest intensity recorded in the month of June for both the species. Monthly Gonado Somatic Index (GSI) shown that the highest feeding was observed in January (10.55%) and July (10.76%) for S. tumbil whereas, in case of S. undosquamis, the GSI was highest in August (16.58% for males and 17.80% for females). The pieces of sand granules, detritus and benthic organisms in the stomachs of the species indicating the benthic nature at the sea bottom in the search of food. Occurrence of juvenile lizardfishes in gut contents of both the species indicates that the lizardfishes are cannibalistic in nature. Key-wordsLizardfish, feeding intensity, Gonado Somatic Index (GSI), Cannibalism INTRODUCTION Lizardfishes belonging to the family Synodontidae and two lizardfishes Saurida tumbil and S. undosquamis are exploited on commercial basis in Indian waters. Food and feeding habits of fish provide the information on the food chain in a particular ecosystem as well as prey and predator relationship and seasonal variations in the diet composition. This information will give the understanding on the migration patterns, abundance and behaviour of the fish. Most of the fishes are highly adaptable in their feeding habits and utilise most of the richly available food . Access this article online Quick Response Code Website:
Indian Fig Cactus (Opuntia Ficus-Indica (L.) Miller) in the Americas: an Uncertain History
Abstract: 
 Opuntia ficus-indica (L.) Miller is a globally important cactus species with a long history of human use. In addition to the importance of O. ficus-indica as a food for humans and livestock, it also has long served a role in the production of cochineal, a once important textile dye. This cactus also is intimately interwoven into the story of Cactoblastis cactorum (Berg) (South American cactus moth), one of the best-known examples of biological weed control. In this regard, O. ficus-indica has been a target weed as well as an unintended host in C. cactorum invasion. Although the distribution and human-assisted movement of this cactus throughout much of the world is well documented, surprisingly little has been written about its history and movement within the Americas. Literature associated with Opuntia and their phytophagous pests in North and South America was examined in an attempt to determine the history of O. ficus-indica in the Americas. Available information suggests with some certainty that O. ficus-indica originated in present-day Mexico, but the timing of its introduction to South America is much less clear. Taxonomic difficulties associated with distinguishing among Opuntia species and the long pre-Columbian history of exchange between South American and Mesoamerican cultures are two primary complicating factors associated with dating the dispersal of this species to South America. Additionally, previous evidence in support of a pre-Columbian introduction to South America relied on questionable identification of insect-based textile dyes. These uncertainties are significant because clearer knowledge of the history of O. ficus-indica introduction to South America could provide a more complete biological and ecological context to efforts at managing this species in its native and introduced ranges, particularly with respect to the threat posed by C. cactorum in North American and Argentinean plantations.