Understanding the process of recruitment is fundamental to fisheries biology and management. However, recruitment in natural populations is highly variable and rarely well described by classical stock–recruitment relationships (SRRs). Recent analyses suggest that the age composition of the spawning biomass may play an important role in the mismatch between SRRs and data. Here we develop a gener...

The importance of kisspeptin in regulating vertebrate reproduction has been well established, but the exact mechanism continues to unfold. Unlike mammals, many lower vertebrates possess a dual kisspeptin system, Kiss1 and Kiss2. To decipher the roles of the kisspeptins in fish, we identified two potential kisspeptin antagonists, pep 234 and pep 359, by screening analogs for their ability to ina...

a. Evaluate efficacy of catfish pituitary extract on spawning induction of pinfish. b. Evaluate dosing of catfish pituitary extract on spawning induction of pinfish. c. Compare human chorionic gonadotropin and catfish pituitary extract on the spawning induction of pinfish. d. Evaluate commercial rotifer enrichments and their effects on larval survival and growth. e. Evaluate larval feeding regi...

Different male germ cells identified on the basis of histological and cytological characteristics in the testicular lobules of Labeo rohita have been grouped into spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatozoa. The seasonal changes of the testis in L. rohita have been described according to its morphological peculiarities as well as to its variations i...

Background: Fluoxetine (ProzacTM) is one of the most popular antidepressant that can be released to aquatic systems via sewage-treatment effluents. It is suspected to provoke substantial effects in the aquatic environment. Methods: In spawning tanks, specimens were exposed to concentrations of 0 and 0.54 µgl-1 fluoxetine from male introduction until the larvae had hatched. Prior to spawning, n...

During 12 months of sampling, from 17 stations, 327 specimens of Soboor fish Tenualosa ilisha, including 120 females, 113 males and 86 immature were caught. Total length (TL) of the fishes was 120-500mm. Maximum diameters of soboor ova 0.795mm and the ova with diameter more than 0.7 mm released at one spawning round. Temporal and spatial distribution of ova diameter corresponding to GSI changes...

The spawning of the muricid gastropod Plicopurpura pansa in the laboratory at 22-23 degrees C is described. Females deposited 1-20 capsules daily for at least 20 weeks, and produced up to 150 capsules each per spawning season. During spawning, egg clusters were formed consisting of hundreds of capsules of different ages deposited by different females. Each egg capsule contained an average of 43...

Induced spawning of fish often requires hormone injections. Preparations used for hormone-induced spawning must be mixed properly, and the correct amount must be used to be effective. This publication describes common techniques used to calculate the hormone concentration and dose, prepare hormone solutions, and inject the fish for induced spawning. To calculate the proper dosage, 1) the recomm...

Circadial spawning times of medusa of the bivalve-inhabiting hydrozoans Eugymnanthea japonica Kubota and Eutima japonica Uchida are confirmed to be morning (possibly sunrise) for the former species and night for the latter. Eugymnanthea, with small, short-lived, univoltine medusae, seems to have evolved from a form similar to Eutima japonica, with larger, longer-lived, multivoltine medusae; the...