Relative pleopod length as an indicator of size at sexual maturity in slipper (Scyllarides squammosus) and spiny Hawaiian (Panulirus marginatus) lobsters

Body size at gonadal maturity is described for females of the slipper lobster (Scyllarides squammosus) (Scyllaridae) and the endemic Hawaiian spiny lobster (Panulirus marginatus) (Palinuridae) based on microscopic examination of histological preparations of ovaries. These data are used to validate several morphological metrics (relative exopodite length, ovigerous condition) of functional sexual maturity. Relative exopodite length (“pleopod length”) produced consistent estimates of size at maturity when evaluated with a newly derived statistical application for estimating size at the morphometric maturation point (MMP) for the population, identified as the midpoint of a sigmoid function spanning the estimated boundaries of overlap between the largest immature and smallest adult animals. Estimates of the MMP were related to matched (same-year) characterizations of sexual maturity based on ovigerous condition — a more conventional measure of functional maturity previously used to characterize maturity for the two lobster species. Both measures of functional maturity were similar for the respective species and were within 5% and 2% of one another for slipper and spiny lobster, respectively. The precision observed for two shipboard collection series of pleopod-length data indicated that the method is reliable and not dependent on specialized expertise. Precision of maturity estimates for S. squammosus with the pleopod-length metric was similar to that for P. marginatus with any of the other measures (including conventional evidence of ovigerous condition) and greatly exceeded the precision of estimates for S. squammosus based on ovigerous condition alone. The two measures of functional maturity averaged within 8% of the estimated size at gonadal maturity for the respective species. Appendage-to-body size proportions, such as the pleopod length metric, hold great promise, particularly for species of slipper lobsters like S. squammosus for which there exist no other reliable conventional morphological measures of sexual maturity. Morphometric proportions also should be included among the factors evaluated when assessing size at sexual maturity in spiny lobster stocks; previously, these proportions have been obtained routinely only for brachyuran crabs within the Crustacea

Lobster breeding, Sea ranching and juvenile fattening

Lobsters are one of the highly esteemed seafood delicacies and cu r re n t ly fetch the highest unit value among commercially exploited marine resources. These are decapod crustaceans belonging to fo u r fami l ie s : Nephropidae {clawed / true lobsters), Palinuridae {Spiny/ rock lobsters), Scyllaridae (Sand /slipper lobsters) and Synaxidae (Coral lobsters). Representatives of the families Palinuridae and Scyllaridae constitute the lobster fisher000y of India

Results of bottom trawl surveys carried out in Vietnamese waters (20-200 m) in 1996-1997

Bottom trawl surveys were conducted in the southwest monsoon season in 1996 (survey 1) and in the northeast monsoon season in 1996-97 (survey 2) throughout Vietnamese waters. The surveys mainly covered the depth zone 50-200 m but in the northeast monsoon season the depth zone 20-50 m was included in the northern and southern areas. Overall, 273 trawl hauls were conducted. The total biomass for Vietnamese waters in the depth zone 20-200 m was estimated at 700 000 t . Biomass estimates are given for the most abundant species. A relatively higher mean catch-per-unit effort (CPUE) was obtained from survey 2 than from survey 1 and in partcular at depth ranges 50-100 and 100-200 m in south Vietnam. Overall, the dominant families were Monacanthidae (34%), Carangidae (15%), Trichiuridae (9%) and Synodontidae (6%)

Comparative cytogenetics in four species of Palinuridae: B chromosomes, ribosomal genes and telomeric sequences

The evolutionary pathway of Palinuridae (Crustacea, Decapoda) is still controversial, uncertain and unexplored, expecially from a karyological point of view. Here we describe the South African spiny lobster Jasus lalandii karyotype: n and 2n values, heterochromatin distribution, nucleolar organizer region (NOR) location and telomeric repeat structure and location. To compare the genomic and chromosomal organization in Palinuridae we located NORs in Panulirus regius, Palinurus gilchristi and Palinurus mauritanicus: all species showed multiple NORs. In J. lalandii NORs were located on three chromosome pairs, with interindividual polymorphism. In P. regius and in the two Palinurus species NORs were located on two chromosome pairs. In the two last species 45S ribosomal gene loci were also found on B chromosomes. In addition, the nature and location of telomeric repeats were investigated by FISH in J. lalandii, P. gilchristi, P. mauritanicus Palinurus elephas, and P. regius (Palinuridae, Achelata), and in Scyllarus arctus (Scyllaridae, Achelata): all these Achelata species showed the (TTAGG)n pentameric repeats. Furthermore, in J. lalandii these repeats occurred in all the telomeres and in some interstitial chromosomal sites, associated with NORs

Facultative secondary lecithotrophy in the megalopa of the shrimp Lysmata seticaudata (Risso, 1816) (Decapoda : Hippolytidae) under laboratory conditions

Certain decapod crustaceans can catabolize internal reserves to undergo partial or full larval development. This feature is termed secondary lecithotrophy, if energy used results from plankton derived organic matter accumulated Ig earlier larval stages. The present work reports the ability of Lysmata seticaudata megalopa to moll to the first juvenile stage in the absence of food. Unlike previous records of secondary lecithotrophy displayed by nonfeeding last larval stages of hermit crabs and spiny lobsters, the megalopa of L. seticaudata retains its feeding capacity. This is the first time such a feature has been reported in decapods, and the term facultative secondary lecithotrophy is proposed. The build up of energy reserves continues during the last zoeal stage of L. seticaudata, with starved zoea IX failing to molt to megalopa. Energy reserves that enable starved megalopa to molt to juvenile seem to be partially depleted, with starved juveniles produced either from, starved or fed megalopae being unable to molt to the next juvenile stage. The longer resistance of starved juveniles produced from fed megalopae (nine days), compared to that of starved juveniles produced from starved megalopae (five days), indicates that some energy reserves may pass to juvenile, not being totally depleted at metamorphosis.info:eu-repo/semantics/publishedVersio

Isolation and characterization of microsatellite markers in the spiny lobster, Panulirus echinatus Smith, 1869 (Decapoda: Palinuridae) by Illumina MiSeq sequencing.

The isolation and characterization of 17 polymorphic microsatellite loci from the spiny lobster Panulirus echinatus (Decapoda: Palinuridae) by Illumina MiSeq sequencing is described..

OCORRÊNCIA DA LAGOSTA Palinustus truncatus A. MILNE-EDWARDS, 1880 (DECAPODA, ACHELATA) NO GRANDE SISTEMA DE RECIFES DO AMAZONAS, BRASIL

The lobster Palinustus truncatus A. Milne-Edwards, 1880, Palinuridae Latreille, 1802, is rarely reported in commercial fisheries in northern Brazilian coast. Two specimens were caught in the area known as Great Amazon Reef System. The specimen was deposited in the carcinological collection.Keywords: Artisanal fishing; biodiversity; brazilian North coast; bycatch.A lagosta Palinustus truncatus A. Milne-Edwards, 1880, Palinuridae Latreille, 1802, é raramente relatada na pesca comercial da lagosta na costa Norte do Brasil. Dois exemplares foram coletados na área conhecida como Grande Sistema de Recifes do Amazonas. O exemplar foi depositado em coleção carcinológica.Palavras-chave: Biodiversidade, costa Norte, fauna acompanhante, pesca artesanal

Reproductive biology and size at onset of sexual maturity of the spiny lobster Panulirus homarus homarus (Linnaeus, 1758) in Khadiyapatnam, southwest coast of India

The size at first sexual maturity is described for females of the Scalloped spiny lobster Panulirus homarus homarus (Palinuridae) sampled from landings at Khadiyapatnam in Kanyakumari district of Tamilnadu, on the southwest coast of India, based on physiological and functional maturity indices. The size at 50% physiological maturity was estimated at 55.0 mm carapace length (CL), based on regression of percent of females with mature, maturing and spent - recovery ovary against carapace length. The smallest female with a mature ovary was 45.5 mm CL compared to the smallest female (46.5 mm CL) with external eggs. Logistic relationships between CL and percentage of females with external eggs (berried) and with ovigerous setae on endopod of pleopods indicated that 50% maturity was attained at 61.0 mm CL (berry method) and 54.0 mm CL (setal method), respectively. Size at maturity based upon appearance of well developed pairs of ‘windows’ on the last pair of sternal plates at the base of fifth pereiopods was estimated at 55.0 mm CL. The analyses show that the external secondary sexual characters may be useful as morphological measures of functional sexual maturity in the spiny lobster Panulirus homarus homarus from Indian waters, as these values are very close to the size at physiological maturity (55.0 mm CL) obtained based on the ovarian maturation. On the basis of this study, a minimum legal size (MLS) of 65.0 mm CL for fishing P. homarus homarus from Indian waters is recommended

Genetic Isolation between the Western and Eastern Pacific Populations of Pronghorn Spiny Lobster Panulirus penicillatus

The pronghorn spiny lobster, Panulirus penicillatus, is a circumtropical species which has the widest global distribution among all the species of spiny lobster, ranging throughout the entire Indo-Pacific region. Partial nucleotide sequences of mitochondrial DNA COI (1,142–1,207 bp) and 16S rDNA (535–546 bp) regions were determined for adult and phyllosoma larval samples collected from the Eastern Pacific (EP)(Galápagos Islands and its adjacent water), Central Pacific (CP)(Hawaii and Tuamotu) and the Western Pacific (WP)(Japan, Indonesia, Fiji, New Caledonia and Australia). Phylogenetic analyses revealed two distinct large clades corresponding to the geographic origin of samples (EP and CP+WP). No haplotype was shared between the two regional samples, and average nucleotide sequence divergence (Kimura's two parameter distance) between EP and CP+WP samples was 3.8±0.5% for COI and 1.0±0.4% for 16S rDNA, both of which were much larger than those within samples. The present results indicate that the Pacific population of the pronghorn spiny lobster is subdivided into two distinct populations (Eastern Pacific and Central to Western Pacific), with no gene flow between them. Although the pronghorn spiny lobster have long-lived teleplanic larvae, the vast expanse of Pacific Ocean with no islands and no shallow substrate which is known as the East Pacific Barrier appears to have isolated these two populations for a long time (c.a. 1MY)