Reproductive dynamics of female spotted seatrout (Cynoscion nebulosus) in South Carolina

We describe reproductive dynamics of female spotted seatrout (Cynoscion nebulosus) in South Carolina (SC). Batch fecundity (BF), spawning frequency (SF), relative fecundity (RF), and annual fecundity (AF) for age classes 1−3 were estimated during the spawning seasons of 1998, 1999, and 2000. Based on histological evidence, spawning of spotted seatrout in SC was determined to take place from late April through early September. Size at first maturity was 248 mm total length (TL); 50% and 100% maturity occurred at 268 mm and 301 mm TL, respectively. Batch fecundity estimates from counts of oocytes in final maturation varied significantly among year classes. One-year-old spotted seatrout spawned an average of 145,452 oocytes per batch, whereas fish aged 2 and 3 had a mean BF of 291,123 and 529,976 oocytes, respectively. We determined monthly SF from the inverse of the proportion of ovaries with postovulatory follicles (POF) less than 24 hours old among mature and developing females. Overall, spotted seatrout spawned every 4.4 days, an average of 28 times during the season. A chronology of POF atresia for water temperature >25°C is presented. Length, weight (ovary-free), and age explained 67%, 65%, and 58% of the variability in BF, respectively. Neither RF (number of oocytes/g ovary-free weight) nor oocyte diameter varied significantly with age. However, RF was significantly greater and oocyte diameter was smaller at the end of the spawning season. Annual fecundity estimates were approximately 3.2, 9.5, and 17.6 million oocytes for each age class, respectively. Spotted seatrout ages 1−3 contributed an average of 29%, 39%, and 21% to the overall reproductive effort according to the relative abundance of each age class. Ages 4 and 5 contributed 7% and 4%, respectively, according to predicted AF values.

Length and age at maturity of female petrale sole (Eopsetta jordani) determined from samples collected prior to spawning aggregation

The problem of bias in female petrale sole age and length-at-maturity relationships caused by sampling from spawning aggregations was investigated. Samples were collected prior to aggregation, and histological methods were used to determine maturity status. Mature and immature fish were classified by inspecting oocytes for the presence of yolk in September, when substantial divergence in yolked and unyolked oocyte diameters had been observed. Comparison of macroscopic and microscopic assessment of maturity showed that maturity status cannot be determined accurately by using macroscopic inspection during the summer. Female petrale sole from the central Oregon coast were 50% mature at 33 cm and 5 years of age. Comparison of data from our study with data used in recent petrale sole stock assessments showed that both sampling bias and the use of samples from sea-sons when status cannot be accurately determined have likely caused errors in fitted maturity relationships.

Nutritional evaluation of fish solubles

This paper reports the results of a preliminary study on the biochemical composition and nutritional charactersitics of fish solubles from oil sardines (Sardinella longiceps) and white tailed pink perch (Nemipterus japonicus). The nutritional quality of sardine solubles has been evaluated by feeding trials using albino rats also. The studies have shown that compared to a control group of rats whose diet had casein as the sole source of protein, a group of rats in whose diet dried sardine solubles replaced half of the casein, had a noticeably higher growth rate. This higher growth rate was not prominent in the early stages of growth (4-7 weeks). But, during later stages (7-10 weeks), solubles incorporated diet supported a distinctly higher growth rate. This effect was more pronounced in female rats (17% over the control group) compared to the male rats (4% over the control group). Fish solubles are found to be poor sources of essential amino acids. Thus, the observed increase in growth rate is higher than the rate expected from the amino acid make up. This probably supports the view expressed by workers elsewhere that fish solubles contain some unidentified growth factors.

Antibiotic resistance of Staphylococcus aureus strains isolated from fish processing factory workers

One hundred and twenty two strains of Staphylococcus aureus isolated from throats and palms of 39 workers from 6 fish processing factories situated in and around Cochin were tested for their sensitivity to nine commonly used antibiotics-ampicillin, chloramphenicol, erythromycin, kanamycin, neomycin, penicillin, polymyxin-B, streptomycin and tetracycline. Highest percentage of resistance was observed towards ampicillin followed by penicillin i.e. 64.75% and 59.84%. Resistance towards other antibiotics like tetracycline, polymyxin-B, erythromycin, kanamycin, neomycin, chloramphenicol and streptomycin were shown by 22.95, 16.39, 7.38, 5.74, 3.28 and 1.64% of the isolates respectively.

A review of spider majid crabs of the northern Arabian Sea, with particular reference to Pakistani species, and with description of an undescribed Pleistacantha

The present report deals with the history of work done on northern Arabian Sea majids, their zoogeographical consideration and recognition of present status of certain genera which are established by recent workers. I have nothing of substance to add to previous treatment by Griffin & Tranter (1986). Emphasis is given to species inhabiting coastal waters of Pakistan. The occurrence of the genus Pleistacantha in the Arabian Sea and its adjacent gulfs is discussed in detail due to presence of a unique female which was taken by Fridtj of Nansen Cruise in 1977. This seems to be an undescribed species. At the moment the female is just given as Pleistacantha sp1 till more specimens obtained determine its position. Some interesting features of Doclea muricata are also considered.