ABSTRACT
Larval descriptions of tropical marine and coastal fishes are very few, and this taxonomic problem is further exacerbated by the high diversity of fish species in these waters. Nonetheless, accurate larval identification in ecological and early life history studies of larval fishes is crucial for fishery management and habitat protection. The present study aimed to evaluate the usefulness of DNA barcodes to support larval fish identification since conventional dichotomous keys based on morphological traits are not efficient due to the lack of larval traits and the rapid morphological changes during ontogeny. Our molecular analysis uncovered a total of 48 taxa (21 families) from the larval samples collected from the Klang Strait waters encompassing both spawning and nursery grounds of marine and estuarine fishes. Thirty-two (67%) of the larval taxa were identified at the species level, two taxa (4%) at the genus level, and 14 taxa (29%) at family level. The relatively low rate of species-level identification is not necessarily due to the DNA barcoding method per se, but a general lack of reference sequences for speciose and non- commercial fish families such as Gobiidae, Blenniidae, and Callionymidae. Larval morphology remains important in species diagnoses when molecular matches are ambiguous. A lower ethanol percentage (50%) for larva preservation is also useful to keep the body of larvae intact for morphological identification, and to preserve DNA for subsequent molecular analyses. The 10% Chelex resin used to extract DNA is also cost- effective for long term monitoring of larval fishes. Hence, the DNA barcoding method is an effective and easy way to aid the identification of estuarine larval fishes at the species level.
ABSTRACT
BACKGROUND: To shorten the waiting time for psychiatric treatment, nurse-led services may help in the first-line mental health consultation and interventions for patients with recent first onset of mental illness. AIMS: The study evaluated the effectiveness of a six-session nurse-led, needs-based psycho-education program for Chinese patients with mental health problems newly referred to an outpatient clinic in Hong Kong, when compared with routine outpatient care. METHOD: A randomized controlled trial with a pre- and post-test, control group design was conducted. Seventy-nine patients were randomly assigned to either the nurse-led psycho-education program (N = 39), or to usual psychiatric outpatient care (N = 40). Multiple patient outcomes and services utilization were measured at recruitment and 2 weeks after the intervention. RESULTS: The results of a multivariate analysis of variance test indicated that the psycho-education group had significantly greater improvements in mental and overall health status, insights into their treatment and illness, and hospitalization rates at the post-test. IMPLICATIONS: The findings provide evidence that nurse-led, needs-based psycho-education can improve mental health, self-efficacy and insights into mental illness in Chinese first-onset mentally ill patients. A future multi-center controlled trial of this nurse-led intervention is recommended.
