On the trail of interannual variability in phytoplankton and climate [abstract and figures]

EXTRACT (SEE PDF FOR FULL ABSTRACT): A selective but nontheless real record of phytoplankton activity over the Santa Barbara Basin can be obtained from the underlying varved sediments. The phytoplankton groups preserved are: diatoms (frustrules and spores), silicoflagellates, dinoflagellates (cysts) and coccoliths.

A mixed culture trail of mud crab (Scylla serrata Forskal) with tilapia ( Oreocromis niloticus L.)

A ten-month study on mixed culture of mud crab Scylla serrata with tilapia (Oreochromis niloticus) was performed in brackish water earthen ponds using live tilapia fry as the only feed for crab. The monthly growth rate varied from 9.07-19.llg among four treatments. Treatment T 1, cw: 0.68cm (±0.72) and bw: 19.11 gm (±12.97) showed highest performance which was followed by T 3, cw: 0.62cm (±0.60) and bw: 13.42 gm (±10.51), T4, cw: 0.65cm (±0.64) and bw: 13.20 gm (±9.89) and T2, cw: 0.36cm (± 0.25) and bw: 9.07 gm (±8.05). Highest survivability of crabs was also recorded in T 1 (21.5%) which was followed by T 2 (15.65%), T4 (14.95%) and T 3 (14.15%). In terms of survivability, significant differences (p<0.05) were observed among the treatments whereas these were recorded as insignificant difference (p<0.05) in final weight, weight gain and production of crabs and tilapia. Mixed culture of mud crab with tilapia could make more rewarding than crab monoculture but the study suggests that only tilapia fry can not fulfill the feed requirement of crabs in respects of survivability, final body weight and weight gain. Besides, existed salinity level of 4-12 ppt during experimental period might be the another key factor for low survivability and weight gain.

Three new club-mosses from Panama

In a previous paper relating to a singular new fern (Polypodium podocarpum) from Panama, I have described very briefly the mountian (sp) region above David in the province of Chiriqui, and have referred in particular to a most interesting collecting trip of three days which I took from El Boquete over "Holcomb's trail" along the Rio Caldera to "Camp I" and to the summit of the Continental Divide a few miles farther on...(Document contains 9 pages)

Herpetofaunal Inventories of the National Parks of South Florida and the Caribbean: Volume II. Virgin Islands National Park

Amphibian declines and extinctions have been documented around the world, often in protected natural areas. Concern for this alarming trend has focused attention on the need to document all species of amphibians that occur within U.S. National Parks and to search for any signs that amphibians may be declining. This study, an inventory of amphibian species in Virgin Islands National Park, was conducted from 2001 to 2003. The goals of the project were to create a georeferenced inventory of amphibian species, use new analytical techniques to estimate proportion of sites occupied by each species, look for any signs of amphibian decline (missing species, disease, die-offs, etc.), and to establish a protocol that could be used for future monitoring efforts. Several sampling methods were used to accomplish these goals. Visual encounter surveys and anuran vocalization surveys were conducted in all habitats throughout the park to estimate the proportion of sites or proportion of area occupied (PAO) by amphibian species in each habitat. Line transect methods were used to estimate density of some amphibian species and double observer analysis was used to refine counts based on detection probabilities. Opportunistic collections were used to augment the visual encounter methods for rare species. Data were collected during four sampling periods and every major trail system throughout the park was surveyed. All of the amphibian species believed to occur on St. John were detected during these surveys. One species not previously reported, the Cuban treefrog (Osteopilus septentrionalis), was also added to the species list. That species and two others (Eleutherodactylus coqui and Eleutherodactylus lentus) bring the total number of introduced amphibians on St. John to three. We detected most of the reptile species thought to occur on St. John, but our methods were less suitable for reptiles compared to amphibians. No amphibian species appear to be in decline at this time. We found no evidence of disease or of malformations. Our surveys provide a snapshot picture of the status of the amphibian species, so continued monitoring would be necessary to determine long-term trends, but several potential threats to amphibians were identified. Invasive species, especially the Cuban treefrog, have the potential to decrease populations of native amphibians. Introduced mammalian predators are also a potential threat, especially to the reptiles of St. John, and mammalian grazers might have indirect effects on amphibians and reptiles through habitat modification. Finally, loss of habitat to development outside the park boundary could harm some important populations of amphibians and reptiles on the island.

Culture of pearl in freshwater mussels (Lamellidens marginalis Lamarck)

A pond trail on pearl culture in freshwater mussels, Lamellidens marginalis was carried out for one year in an artificial perennial pond. Four types of foreign particles of indigenous sources, sand, stone, fish eyeball and beads of artificial pearl nucleus were used as nucleus for pearl production. Among the nuclei inserted mussel highest survival rate (72%) was recorded for stone and lowest survival rate (50%) for artificial pearl by nucleus implantation. Highest pearl production rate (%) was recorded for the insertion of stone and lowest for the sand. All nuclei inserted mussel produced pearl accept the mussel which was inserted beads of pearl nucleus for pearl formation. Growth rate (length and weight) was found higher for uninserted mussel than nuclei inserted mussels.

Effect of feeding frequency on the growth of common carp (Cyprinus carpio L.) fry

A laboratory-feeding trail was conducted for 45 days with fry of common carp Cyprinus carpio L. (0.45±0.03g) in aquaria in a static indoor fish rearing system. The fry were fed on a pelleted diet containing 33% crude protein having fishmeal as major protein source. The fish fry in five treatments A, B, C, D, and E, each with two replicates were fed on 5% daily ration divided into different feeding frequencies of 2, 3, 4, 5 and 6 times a day respectively in order to observe the growth performance. Each replicate contained 15 fry having total initial weight of 6.87±0.31g. At the end of the feeding trial, significantly different and higher (p<0.05) growth response was observed in treatment C having a feeding frequencies of 4 times a day. Significantly the highest and the lowest percent growth of 334.30 and 218.91% were observed in fish fed on the diet (Treatment C) with 4 times and (Treatment A) 2 times feeding frequencies per day, respectively. Food conversion ratio (FCR) of 1.78 was significantly higher (p

Effects of black Bengal goat manure on growth and production of Genetically Improved Farmed Tilapia (GIFT) starin [sic], Oreochromis niloticus

In a goat-tilapia integrated farming system, the effect of Black Bengal goat manure on the growth and production of Oreochromis niloticus was studied at the Freshwater Substation, Shantahar, Bogra for 4.5 months. The stocking density used in three treatments were, 200 goats and 15,000 GIFT strain/ha (T1); 300 goats and 15,000 GIFT strain/ha (T2); and only 15,000 GIFT strain/ha (T3). The initial individual total length and weight of stocked tilapia were 7.6 cm and 11.34 g, respectively. Twelve ponds each having an area of 40 square meters were used for this trail [sic]. On one side of each pond goat shed was constructed and the space allocated for each goat was 0.75 m x 1.5 m. Newly weaned black Bengal goats of average weight 8.45 kg was used in the trial. Every morning the goats manure was swiped out in ponds through the fixed opening of bamboo made floor of goat shed. Water depth of the ponds was maintained at 0.75 m. The highest fish production was in treatment 1 (1,750 kg/ha) followed by treatment 2 (1,455 kg/ha) and treatment 3 (621 kg/ha). The difference in individual goat weight was not significant (P>0.05) among treatments 1 and 2.

Effects of dietary vitamin E on the growth and breeding performance of Ompok pabda

A 90 day feeding trail was conducted to investigate the effect of vitamin E on the growth and breeding performance of Ompok pabda. A total of 84 healthy female brood fish (41.10±0.44g) were divided into 4 treatments i.e. treatment T1 T2, T3 and T4 having three replications each. The fish were fed twice a day with a standard feed (40% protein) having 4 doses of vitamin E viz. 0 (served as control), 50, 100 and 150mg vitamin E/kg feed. At the end of the feeding trial, the brood fish were induced to breed with PG extract to observe the effect of vitamin Eon feed. After rearing for 90 days with the experimental feeds, it was found that weight gain and specific growth rate of brood fish fed with 100mg vitamin E/kg feed (treatment T3) was the highest (14.78±0.38g and 2.99±0.11) while 150mg vitamin E/kg feed (treatment T4) fed fish gave the poorest result (2.97±0.89g and 1.21±0.32). There was no significant difference in terms of length gain of brood fish among the different treatments. The brood fish were induced to breed with equal dose of PG extract (18 and 12mg PG/kg body weight for female and male respectively) to observe the dietary effect of vitamin E on breeding performance. The highest ovulation, fertilization and hatching rate of eggs were found to be 81.48±6.41%, 84.04±3.53% and 68.59±5.03% respectively in the brood fish of treatment T1 while the poorest (33.33±00%, 52.35±5.02% and 45.70±7.24% respectively) were found in the brood fish under treatment T4. The results suggest that inclusion of 100mg vitamin E/kg feed is best for enhancing the breeding performance of O. pabda brood fish indicating that vitamin E content has a positive impact on reproduction of fish. The present results also imply that inclusion of higher level of vitamin E exerts an antagonistic effect in terms of growth and breeding performance of this species.