Total Body Length (total + body_length)

Distribution by Scientific Domains

Selected Abstracts


Lisa Mignon Rotterman
Abstract After the 1989 T/V Exxon Valdez oil spill (EVOS), the body condition of non-pregnant female sea otters (Enhydra lutris) ages 4 yr and older in the EVOS-affected region of western Prince William Sound, Alaska (WPWS), was significantly poorer than that of individuals captured in the same or adjacent habitat in WPWS approximately a decade earlier, and than that of individuals inhabiting unoiled habitat in eastern PWS (EPWS) between 1984 and 1990. However, the body condition of females of this age category captured in WPWS prior to EVOS was not significantly different from that of pre-and postspill EPWS females. The mean total body length (TBL) of non-pregnant females captured prespill in WPWS was significantly less than that of pre-and postspill EPWS and postspill WPWS females. Evidence from this and other studies suggests that the body condition of at least some classes of sea otters was negatively affected by one or more EVOS-related factors. [source]

Emigration patterns among trout, Salmo trutta (L.), kelts and smolts through spillways in a hydroelectric dam

Abstract, The emigration patterns among radio-tagged trout, Salmo trutta L., kelts (n = 41, total length: 60,90 cm) and smolts [n = 27, total body length (BL): 22,30 cm] in the regulated River Gudbrandsdalslågen, south-east Norway, were studied by investigating the influence of sex (kelts) and BL (kelts and smolts) on the timing of emigration. In total, 49% of the kelts emigrated towards the hydroelectric dam shortly after spawning, whilst 51% over-wintered. Female kelts were five times more likely to initiate autumn emigration, and eight times more likely to descend the spillways during the first release of surface water than males. Large individuals of both sexes descended earlier than smaller individuals. Larger smolts were more likely to descend during the first release of surface water than smaller smolts. To safeguard the emigration of iteroparous trout kelts and smolts, the spillways should release surface water both in autumn and spring to avoid selective forces during emigration through spillways. [source]

Prespawning migratory behaviour and spawning success of sea-ranched Atlantic salmon, Salmo salar L., in the River Gudenaa, Denmark

K. Aarestrup
The migratory behaviour of sea-ranched Atlantic salmon, Salmo salar L., was analysed by radio-telemetry in the River Gudenaa, Denmark. The main objectives were to: (1) estimate mortality of returning adults through the fjord; (2) observe rate of progression and migratory pattern in the fjord and river; and (3) record whether spawning occurs in the river. Forty-two returning salmon (19 males and 23 females of total body length from 60,97 cm) reared and released as smolts, were caught and equipped with external radio transmitters in the outer estuary of the River Gudenaa in 1994 and 1995. Of the tagged salmon, 18 (43%) were caught in the estuary, four (10%) were not recorded after release and 20 (47%) entered the river. The mean rate of progression through the fjord was 7.6 km d,1 (range 1.4,18.2) in 1994 and 5.4 km d,1 (range 1.6,17.1) in 1995. Eleven salmon were alive at the onset of the spawning period. Eight were retrieved dead from the river during or after the spawning period; four with empty gonads assumed to be successful spawners, and four with intact gonads. In 1994, unsuccessful spawners (found dead with intact gonads) entered the river earlier and had a longer total migration distance in the river compared to successful spawners. This suggests that spawning success of sea-ranched salmon is associated with time of river entry and river migration length. [source]

Effects of exploitation on reproductive capacity of blackspot snapper, Lutjanus fulviflamma (Pisces: Lutjanidae) in Mafia Island, Tanzania

A. T. Kamukuru
Abstract There is paucity of information on the effects of exploitation on reproductive characteristics of blackspot snapper, Lutjanus fulviflamma (Forsskål 1775) in Tanzanian coastal waters. We compared size at first sexual maturity (LM50), sex ratio, fecundity, and breeding season of L. fulviflamma in least fished Mafia Island Marine Park (MIMP) and intensively fished areas (IFA) between May 1999 and April 2001. Fish in MIMP matured at significantly smaller size (female: LM50 = 206.3 mm; male: LM50 = 195.5 mm) than in IFA (female: LM50 = 216.7 mm; male: LM50 =212.1 mm) total body length. Sex ratio was balanced at 1.03 : 1 (female : male) in MIMP, but it was skewed 0.9 : 1 (female : male) in IFA. Size-related differences in sex ratio were observed with males predominating in the smaller sizes and females in the larger sizes. Total fecundity of fish in MIMP was determined at 45,200,430,200 oocytes in females of between 207 and 293 mm total length. Lutjanus fulviflamma in MIMP has a prolonged spawning season lasting from September to March peaking in December. None of the fish from IFA were in breeding state, suggesting recruitment overfishing is an added matter of concern for the long-term sustainability of the fishery at the current exploitation level. Résumé Il existe très peu d'informations sur les effets de l'exploitation sur les caractéristiques de la reproduction de Lutjanus fulviflamma (Forsskål 1775) dans les eaux côtières de Tanzanie. Nous avons comparé la taille au début de la maturité sexuelle (LM50), le sex-ratio, la fécondité et la saison de reproduction de L. fulviflamma dans le Parc Marin de l'Ile de Mafia (MIMP) où la pêche est moins intense et dans des eaux intensément exploitées (IFA) entre mai 1999 et avril 2001. Les poissons du MIMP deviennent mâtures tout en ayant une longueur totale significativement plus petite (femelles: LM50 = 206,3 mm; mâles: LM50 = 195,5 mm) que dans les IFA (femelles: LM50 = 216,7 mm; mâles: LM50 = 212,1 mm). Le sex-ratio est équilibréà 1,03/1 (femelles/mâles) dans le MIMP, mais il est de 0,9/1 (femelles/mâles) dans les IFA. On a observé des différences du sex-ratio liées à la taille, avec les mâles qui prédominent dans les plus petites tailles et les femelles dans les plus grandes. On a déterminé la fécondité totale dans le MIMP, entre 45.200,430.000 ovocytes à l'intérieur des femelles comprises entre 207 et 293 mm de longueur totale. Dans le MIMP, Lutjanus fulviflamma a une saison de frai prolongée, allant de septembre à mars avec un pic en décembre. Aucun des poissons des IFA n'était en période de reproduction, ce qui signifie une sur-pêche du potentiel reproducteur, ce qui est un motif d'inquiétude pour la durabilitéà long terme de la pêche à son niveau actuel. [source]

Effects of Dietary Heat-killed Lactobacillus plantarum on Larval and Post-larval Kuruma Shrimp, Marsupenaeus japonicus Bate

Ha Thanh Tung
Two feeding trials were conducted to evaluate the effects of heat-killed Lactobacillus plantarum (HK-LP) on larval and post-larval kuruma shrimp, Marsupenaeus japonicus Bate. Five microbound diets were formulated to contain levels of a preparation containing 20% HK-LP (HK-LP Prep): 0, 0.001, 0.01, 0.1, and 1 g/kg. In the first experiment, zoea1 stage larvae were fed test diets for 8 d. Some parameters such as survival, developmental stage, metamorphosis to post-larvae, and formalin stress resistance were evaluated. In second trial, post-larval shrimp (16 ± 0.04 mg) were fed test diets for 30 d. Survival, body weight gain, specific growth rate, feed efficiency ratio, individual dry weight, total body length, osmotic and formalin stress resistances, and protease activity were evaluated. Results indicated that the larvae that received HK-LP Prep at 0.1 and 1 g/kg diets showed significantly (P < 0.05) higher survival than that of the control group. For the post-larval trial, shrimp that received HK-LP Prep at 1 g/kg diet were significantly higher than the control group in most of the growth parameters and stress resistance. However, shrimp that received HK-LP Prep at 0.1 g/kg diet were significantly higher than the control group in survival only. For protease activity, there was no significant difference detected among groups. [source]

Size variation and mating success in the stag beetle, Lucanus cervus

Abstract The stag beetle, Lucanus cervus, is Britain's largest beetle, with a patchy distribution in southern England. The literature suggests that it displays exceptional size variation, particularly in the males, but no analysis of size inequality has ever been conducted. In the present study, stag beetle adults are measured and allometric relationships derived between various parameters and total body length. Most of the specimens found each year are fragments and head width can be used as a good predictor of total body length in each sex. Body size differs between years and between localities and male beetles show a greater degree of size inequality than females. However, L. cervus does not show greater inequality in size than many other beetle species and populations of males are composed of a relatively large number of small individuals. These males are not at a disadvantage in mating because it is the ratio of male : female size that determines mating success. Very large males are less successful in mating and it is suggested that lack of mating success may act as an additional constraint on mandible size in this species. Size variation is most likely caused by variation in larval food resources, coupled with variation in local climatic conditions. [source]

Development of testis and digestive tract in longnose gar (Lepisosteus osseus) at the onset of exogenous feeding of larvae and in juveniles

Marta Jaroszewska
Abstract The aim of this study was to describe the ontogenetic development of the testis and the alimentary tract in longnose gar (Lepisosteus osseus) related to fish size and age at the onset of exogenous feeding and late ontogenesis. Using light microscopy, testes were first detected histologically by the appearance of primordial germ cells 9 days after the first exogenous feeding [31,31.5 mm total body length(TL)] and presumptive seminiferous tubules (maleness characteristic) in fish of 107 mm TL. The present histological studies indicated that the alimentary tract of lepisosteids is completely functional at the beginning of exogenous feeding, several days before the completion of yolk absorption. Based on these results, we have concluded that garfish larvae/juveniles can be effectively trained to consume formulated diets at early stages, after an initial feeding of live food for 2,3 days (23.5 mm TL). Our findings provide evidence of the first controlled rearing of longnose gar using live and formulated diets, providing the possibility of experimental work with this non-teleost fish. [source]

The medial and lateral bellies of gastrocnemius: A cadaveric and ultrasound investigation

Tony Antonios
Abstract It is commonly reported that the medial belly (MG) of the gastrocnemius muscle extends further distally than the lateral belly (LG). This observation is made in several standard anatomy texts with no explanation or quantitative data. In this study, the medial and lateral bellies of gastrocnemius in 45 embalmed cadavers were measured. The observed difference in length of the two bellies was found to be highly significant (mean difference in length = 1.74 cm, P < 0.001). In 8 out of 84 legs examined (9.5%), however, the MG was found to be shorter than the LG (three right legs, five left legs, bilateral in two individuals). Surprisingly, there was no correlation between the difference in muscle belly length in any individual and ipsilateral leg length or total body length, suggesting that the difference in belly length may be unrelated to biomechanical function. An ultrasound investigation into the activity pattern of the two bellies was carried out on five volunteers. Muscle activity was monitored during passive and active movements of the ankle and knee joints at different leg positions. During knee flexion and ankle plantarflexion, the LG contracted first in four of the five subjects, followed by the MG, then a period of either LG predomination or equal contraction. The fifth subject, who showed a reversed pattern of activity, had previously suffered an inversion injury of the ankle. We suggest that the initial activation of the LG may help to stabilize the ankle during plantarflexion. We found no evidence that gastrocnemius acts as a shunt muscle during distraction of the knee. Clin. Anat. 21:66,74, 2008. © 2007 Wiley-Liss, Inc. [source]


Susan E. Cosens
Abstract To determine whether Hudson Bay-Foxe Basin bowhead whales segregate on the basis of age, whales summering in northern Foxe Basin, were aerially photographed in August of 1996, 1997, and 1998. Image lengths on either the negatives or contact prints were measured and total body lengths were estimated. In all three years the majority of whales photographed were ,13.5 m long. Calves and juveniles made up 89.3%, 96.6%, and 79.3% of the total number of measured whales in 1996 (n = 28), 1997 (n = 30) and 1998 (n = 29) respectively. The number of bowheads >13.5 m, the approximate size at which females reach sexual maturity, that were photographed was directly proportional to the number of calves photographed. Our results indicate that northern Foxe Basin bowheads are part of a more widely distributed stock. Adult males and resting adult females apparently summer in another part of the range, probably northwestern Hudson Bay. Northern Foxe Basin appears to be used as a summer feeding area by cows with young-of-the-year calves and by juveniles. [source]