Years In Captivity Research Articles

Life‐history traits of gaurBos gaurus: a first analysis

ABSTRACTIn this first detailed analysis of gaurBos gauruslife‐history traits, data were collected from a 20‐month field study in South India and from captive gaur populations. Mean age of females at first parturition was 3 years; females remained fertile beyond the age of 15 years. Adult females were three times more abundant than adult males in the wild; survival of females was greater than males beyond three years of age. Life span of both sexes has not exceeded 24 years in captivity. Gaur life‐history traits are similar to those of other similar‐sized Bovini species.

Annual variation in the biochemical composition of newly hatched larvae of Maja brachydactyla in captivity

Quality of newly hatched larvae (NHL) of Maja brachydactyla in captivity has been characterized throughout the year to evaluate their availability for mass production. Spawning took place every month and NHL were collected and analyzed to estimate individual dry weight (DW) and proximate biochemical composition (protein, carbohydrate and lipids). Lipid class, fatty acid composition, amino acid profile, mineral and vitamins A, E and C contents were analyzed seasonally. NHL obtained throughout the year are a potential source for aquaculture purposes, since the increment in the relative protein and lipid (especially phospholipids and n-3 PUFA) content might compensate the decrease in DW of larvae hatched from broodstock kept during one year in captivity. However, the decrease in vitamins A and E as well as in certain essential amino acids (Lys, Val, and His) and trace elements (Cu and Fe) of NHL at the end of the year might be indicative of a nutritional deficiency in broodstock diets.

Remote sensing of physiological data: Impact of long term captivity on body temperature variation of the feral cat ( Felis catus) in Australia, recorded via Thermochron iButtons

This study reports body temperature regulation ( T b) and circadian rhythms of undisturbed feral cats in their natural environment in Australia over a continuous period of three months. It furthermore compares these data with T b data collected of feral cats, after a period of one year in captivity. In free-ranging, undisturbed feral cats, a distinct robust, regular circadian rhythm (strength of rhythm) (21–59.8%) with higher body temperature in the dark (active) phase (mean±STD: 39.2±0.27 °C) and significantly lower body temperature during the light (rest) phase (mean±STD: 38.1±0.47 °C, P<0.001) was found. The acrophase (time of the daily peak) of the three free-ranging cats investigated varied from 22:34 h (LG 2), 22:57 h (LG 1) to 23:17 h (LG 3). In the course of captivity, the cats’ circadian rhythms shifted from nocturnality to a diurnal tendency, with an acrophase ranging from 12:00 h (MtK 2), 12:23 h (MtK 1) to 16:25 h (MtK 3). This change in rhythmicity was accompanied by a significant decrease in robustness (1.7–5.2%) and mean body temperature levels (37.77±0.34 °C) as well as minima and maxima (36–39 °C versus 35.5–41.9 °C, free-ranging cats) of three captive cats, resulting in a significant shift towards a decrease in amplitude. These striking differences of circadian rhythms between domestic and free-ranging feral cats highlight the importance of remote body temperature measurements to understand the physiological differences between captive and free-ranging animals.

Uropygial gland size correlates with feather holes, body condition and wingbar size in the house sparrow Passer domesticus

The uropygial gland is an organ exclusive of birds that secretes an oily substance, the uropygial secretion, the functions of which are still debated. One of the proposed hypothesis is its possible action against chewing lice (order Phthiraptera), a group of avian ectoparasites that feed on feathers, causing different types of harm. However, this hypothesis lacks support. The present study analyses the relationship between uropygial gland size and the number of feather holes (which is correlated with the load of chewing lice) in the house sparrow Passer domesticus. Moreover, the relationship between the uropygial gland size and different aspects of sparrow health (body condition, immunocompetence and haematocrit), as well as sexually selected traits in males (badge and wingbar size), is tested. The results show a negative correlation between uropygial gland size and number of feather holes, a result found both years of the study. This result supports the hypothesis that uropygial secretion is used against chewing lice. Uropygial gland size also correlated positively with body condition (residuals of body mass relative to tarsus length) and immunocompetence, being therefore related to bird health. After a year in captivity, with resources provided ad libitum, no correlation was found between individual uropygial gland size and body condition or haematocrit, perhaps because the negative effect that chewing lice exert on bird health was offset by captivity conditions. Uropygial gland size was not correlated with badge size, but it was correlated with wingbar size, which furthermore supports the contention that this sexually selected signal acts as an indicator of lice resistance in the house sparrow. In summary, this study supports the idea of a positive relationship between uropygial gland and bird health in the house sparrow, the gland secretion affording resistance against chewing lice.

Daily and seasonal activity patterns of partially migratory and nonmigratory subspecies of the Australian silvereye, Zosterops lateralis, in captivity

We recorded the locomotor activity of the partially migratory Tasmanian silvereye, Zosterops l. lateralis, and the nonmigratory mainland silvereye, Z. l. familiaris, continuously over 17 and 15 months, respectively, to identify daily and seasonal patterns. While graphing the data showed several trends, statistical analysis did not reveal a significant difference between subspecies, making this study mainly descriptive in nature. The lack of statistical differentiation was possibly due to the low number of study animals and similarities between them. During the first year in captivity, the Tasmanian birds displayed heightened activity during the migratory periods, which was most likely migratory restlessness. The Tasmanian birds did not show any nocturnal activity as in previous laboratory and field studies, rather their activity patterns were similar to those of diurnal migrants, possibly reflecting the temporally variable nature of their migration. Although the Tasmanian birds displayed higher overall activity levels than the mainland birds during the first year in captivity, the activity patterns were similar between the subspecies. Captivity appeared to influence the activity of both subspecies in the second year of the study; following the onset of molt, neither subspecies regained the activity levels of the previous year, nor did activity follow the same pattern. Possible reasons (e.g., prevention of breeding) for this are discussed. This is the most detailed study to date on the daily and seasonal activity patterns of an Australian bird in captivity.

Impacts of animal traffic on the Brazilian Amazon parrots (Amazona species) collection of the Quinzinho de Barros Municipal Zoological Park, Brazil, 1986-2007

Eleven species of Amazon parrots (genus Amazona) are known to occur in Brazil, and nest poaching and illegal traffic pose serious conservation threats to these species. When the illegal owners realize these animals are incompatible with their expectations and lifestyle, or when the police arrests traders and owners, these trafficked animals are often considered unfit for release and sent to local zoos and captive breeders. A retrospective survey of animal and necropsy records from 1986 to 2007 was used to evaluate the impacts of animal traffic on the population composition and mortality patterns of Amazon parrots at the Quinzinho de Barros Municipal Zoological Park, Sorocaba, Brazil. Data were obtained for 374 Amazon parrots of ten Brazilian species, and there was evidence that the studied population could be split into two major groups: a majority belonging to the Amazona aestiva species and a minority belonging to the remaining species. In comparison, the animals of the first group were more frequently admitted from traffic-related origins (98 vs. 75%), had a shorter lifespan (median 301 days vs. 848 days) and a higher mortality within the first year postadmission (54 vs. 37%), were less likely to receive expensive treatments, and were more frequently housed off-exhibit. On an average, parrots were found to have a short postadmission lifespan (median 356 days), with 92.5% of the birds dying within their first five years in captivity. The paper discusses the difficult dilemmas these incoming traffic-related animals pose to zoo management and official anti-traffic policies.

Suspected viral erythrocytic necrosis (VEN) in a juvenile blackbar triggerfish, Rhinecanthus aculeatus, from Lizard Island, Great Barrier Reef, Australia

Suspected viral erythrocytic necrosis (VEN) was detected in blood films from an immature blackbar triggerfish, Rhinecanthus aculeatus, captured on a patch reef at Lizard Island, Great Barrier Reef in November 2005, probably the first record of such an infection from Australia. The fish was kept in captivity and sampled intermittently until December 2007. Giemsa-stained blood films showed initially 18% of mature erythrocytes affected by the VEN-like condition, but accompanying erythroblasts appeared free from infection. Erythrocytes with VEN-like bodies were smooth or crenated in outline, while the inclusion bodies were intracytoplasmic, single or paired, round in outline, stained deep magenta and were between 0.5–1.7 mm across. Bodies associated with clouds of granular material, fine eosinophilic haloes, and distinct pink-stained comet-tails, were also observed. The DNA content of the VEN-like bodies was confirmed by their green fluorescence following acridine orange staining. Infection levels in this fish fell to 0.4% of mature erythrocytes by May 2006 and persisted at this level until December 2007, when the fish died after just over two years in captivity. Squashes of haematophagous, juvenile gnathiid isopods taken from this fish on initial capture, also contained eosinophilic VEN-like bodies within digesting erythrocytes, suggesting that these crustaceans may be vectors of the condition observed.

SH07 COATES AND DUNLOP – ART PATRONS OF THE BURMA RAILROAD

Over one hundred thousand British, Dutch, Australian and American troops became prisoners of the Japanese when they invaded Singapore in 1942; twenty thousand of them were Australians, members of the second AIF. One in four died as Prisoners‐of‐War (POW). Their torment and torture at the hands of the Japanese during three years of captivity – both in Changi prison camp and as slave labour on the Burma‐Thailand railway – have been the subject of many books. In the absence of photography the graphic record of cruelty and hardship and the pain and suffering of the POW's on the Burma railway depended upon a few talented artists. Opportunities to record these scenes and particularly some of the medical conditions encountered were provided and encouraged by their senior medical officers. The role of Albert Coates and ‘Weary’ Dunlop in providing leadership and inspiration for these artists under trying circumstances is discussed in this paper.

Darwin, Earthworms &amp; Circadian Rhythms: A Fertile Field for Science Fair Experiments

[ILLUSTRATION OMITTED] Darwin & Earthworms Strange noises, including shouts, whistling, and music, from the playing of a bassoon and a piano, echoed from Down House in Downe, England. However, it was not a festive 19th century social occasion; instead, a careful scientific experiment was being conducted by the ever-curious naturalist Charles Darwin (1809-1882). Cooperative earthworms, Lumbricus terrestris, were being tested to see if they would react to sound. He also investigated their sensitivity to light, vibrations, odors, and touch. For his work, he kept earthworms in soil-filled flowerpots in his library. Darwin suffered from chronic insomnia, a condition that no doubt led to his making so many observations of the nocturnal earthworm. Intrigued with their everyday behavior, Darwin wondered just how smart earthworms were. After watching earthworms plug up their burrows with petioles, leaves, pebbles, or twigs wedged in subtly different ways, Darwin concluded that they possessed a surprising level of intelligence. After watching them manipulate pine leaves, Darwin commented order, therefore, that worms should do their work well, they must drag pine leaves into their burrows by their bases, where the two needles are conjoined. But how they are guided in this work is a perplexing question (Darwin, 1881). For one experiment, Charles Darwin and his son Francis cut the sharp ends from the pine needles, but found that the earthworms still preferred to drag the needles into their burrows by the bases. It appeared both to my son and myself as if the worms instantly perceived as soon as they had seized a leaf in the proper manner (Darwin, 1881). How the eyeless earthworm gains an overview of individual leaves so as to be able to maneuver them was not readily understood, but it was thought to depend mainly on the earthworm's tactile sense. In Charles Darwin's book, The Formation of Vegetable Mould through the Action of Worms, there are measurements and calculations that the Darwins made of the weight of the nightly manure castings produced by earthworms, and consequently how much of an accumulation of this mould would build up over the years. Such detailed observations and careful attempts to numerically quantify various natural processes are found throughout Darwin's writings. The earthworm's relatively simple digestive system, consisting of a mouth, pharynx, esophagus, crop, gizzard, and intestine, enables it to grind vegetable matter and other stray material that it ingests to produce the clay-like manure castings egested from its anus and deposited on the ground's surface. This relentless activity mixes and enriches the topsoil to create fertile humus. Generally, earthworms live less than three years, but some have been known to live as long as six years in captivity. The age at which earthworms reach sexual maturity varies greatly based on season, environmental temperature, food availability, and moisture content of the soil. (Further information, as well as good photographs and drawings of dissected earthworms, can be found online with a GoogleTM search.) The reproduction of earthworms is of particular interest. Both male and female reproductive organs are found in the same individual. In general, organisms are classified as diecious (two houses) if male and female reproductive organs are in separate individuals, and monecious (one house) if both types of organs are in one individual, as is the case for earthworms. Even though earthworms are monecious, they cannot self-fertilize. The common earthworm comes to the surface of the ground to mate on damp summer nights. Reproductive readiness is evident by the swollen clitellum, an enlarged region seen partway down the length of the body from segments, or metameres, 31 or 32 to 37. During mating, they position themselves so that the flat, ventral parts of their bodies are together, and their head ends point in opposite directions, which is necessary so that the genital pores match up. …

162 REPRODUCTIVE CYCLES, PREGNANCY AND REVERSAL OF LONG TERM ACYCLICITY IN CAPTIVE SOUTHERN WHITE RHINOCEROS AT HAMILTON ZOO

In 1999, the New Zealand captive population of Southern white rhinoceros (Ceratotherium simum simum) was increased with the addition of six wild-caught founders. We report on the breeding success of two females (est. 5 to 6 years at import) and a female born in 2000 (conceived in the wild). Fecal samples were collected 1 to 3 times per week from females (n = 3) for several periods (5 to 24 months) between 2000 and 2008. Reproductive cycles and pregnancy were characterized using fecal progestogen concentrations, observations of courtship behaviour and parturition dates. The average length of the reproductive cycle was 31.6 ± 0.6 days (range 26–38 days, n = 34 cycles). Four pregnancies were confirmed in one female with a sex ratio of 1 female to 3 males (including 1 male loss at an estimated 5 months of gestation), known gestation lengths were 514 and 507 days. In the non-reproducing adult female, long cycles (67.2 ± 1.3 days, n = 5) were detected in addition to regular cycles (31.9 ± 0.9 days, n = 13) during the first 3 years in captivity, consistent with previous reports (Schwarzenberger F et al. 1998 An. Repro. Sci. 53, 173–190; Brown JL et al. 2001 Zoo Biol. 20, 463–486). The absence of breeding behavior and low progestogen concentrations for an extended 4-year period was cause for concern for the Australasian Species Management Programme managers (Hermes R et al. 2004 An. Repro. Sci. 82–83, 49–60; Hermes R et al. 2006 Theriogenology 65, 1492–1515). In 2007, the social structure of the Hamilton Zoo rhinoceros group was altered by exchanging the breeding male and two male offspring for a wild-caught male from Auckland Zoo. Within two months of arrival the long-term acyclic female had resumed cycling and had conceived six months after introduction of the new male. The young captive-born female continued to have regular length cycles and mating was observed with the new male. Recently, early embryonic loss was determined by ultrasound in the young female having a long 70 day cycle determined by fecal analysis. Fecal progestogen concentrations were useful for diagnosing pregnancy after 3 months gestation with concentrations four times higher than luteal phase concentrations by 9 to 12 weeks after mating (n = 3). Two females exhibited seasonal acyclic periods characterized by low progestogen concentrations corresponding to decreasing daylength (autumn and winter months). Fecal progestogen monitoring of reproductive status and pregnancy combined with behaviour observations has provided valuable information for breeding management decisions and planning for parturition in this population. The reversal of long-term acyclicity and a resulting pregnancy that represents two original founders is particularly significant for the genetic diversity of the Australasian population of white rhinoceros.

Looks can deceive: Molecular identity of an intraerythrocytic apicomplexan parasite in Australian gliders

Two yellow-bellied gliders ( Petaurus australis) had an intraerythrocytic parasite closely related to the cyst-forming coccidia (Apicomplexa: Sarcocystidae). The parasitaemia persisted for 3 months or more but was observed to clear within 3 years in captivity. The parasite appears not to significantly debilitate its infected host. Traditionally, using morphological identification, the intraerythrocytic parasite would have been classified within the Hepatozoon species typically found in red blood cells. However, molecular diagnostic techniques targeting the parasite's SSU rDNA and LSU rDNA demonstrated the unusual identity of this blood parasite and disputed its identity as a haemogregarine parasite of the genus Hepatozoon. The sequence was compared with available sequences from diverse mammalian and non-mammalian blood parasites (malaria, piroplasms, hemosporidia and sarcosporidia). The intraerythrocytic blood parasite was found to be most closely related to the cyst-forming coccidia including Besnoitia spp., Cystoisospora spp., Hammondia spp., Hyaloklossia lieberkuehni, Neospora caninum, Sarcocystis spp. and Toxoplasma gondii. The life cycle of this intraerythrocytic parasite remains unknown. The presented DNA identification demonstrates its suitability for an improved identification of blood parasites.

Contribution of research to conservation action for the Northern Bald Ibis Geronticus eremita in Morocco

AbstractThe Northern Bald Ibis or Waldrapp Geronticus eremita is a species of arid semi-deserts and steppes, which was formerly widely distributed as a breeding bird across North Africa, the Middle East and the European Alps. Just over 100 breeding pairs now remain in the wild at two sites in Morocco whilst two further wild pairs remain in Syria. There is also a population in Turkey, which is maintained for part of the year in captivity, and a large captive population in zoos. The species is classified by IUCN as ‘Critically Endangered’, the highest threat category. The wild population has grown during the past decade, which represents the first evidence of population growth in the species' recorded history. Conservation action in Morocco has contributed to this recovery. A large part of the contribution of research to conservation action has been to establish and document the value of simple site and species protection. Quantitative assessments of the importance of sites for breeding, roosting and foraging have helped to prevent disturbance and the loss of sites to mass-tourism development. Wardening by members of the local community have reduced disturbance by local people and others and increased the perceived value of the birds. Monitoring has suggested additional ways to improve the breeding status of the species, including the provision of drinking water and removal and deterrence of predators and competitors. These actions have been evaluated by subsequent testing. Steppe and two-year fallows were shown to be the key feeding habitats, and maintaining such non-intensive land uses in future may present major management challenges. The recovery in the Souss-Massa region remains precarious because the population is concentrated in a few places where adverse changes are possible. However, it could provide opportunities for natural extension of the range to formerly occupied sites further north in Morocco.

Care, husbandry and diseases of the African giant rat (Cricetomys gambianus) : review article

The African giant rat lives up to 14 years in captivity, reaching maximum body weights of approximately 2.80 kg in bucks and 1.39 kg in does. In Britain, the African giant rat is increasingly becoming a popular exotic pet. A survey was conducted on 41 licensed pet shops in the UK. The range of ages of giant rat presented for sale, single price per rat, paired prices (buck and doe) and transport costs were 4-12 weeks, pounds sterling 320-pounds sterling 370, pounds sterling 352.50-400.00 including VAT, and pounds sterling 10-37.50, respectively Ivermectin injected at 200-400 microg/kg subcutaneously once a week for 3 weeks will eliminate ectoparasites (and many endoparasites). Nematode infections can also be treated with fenbendazole or piperazine. Bladder threadworms can be treated with fenbendazole, protozoa with metronidazole (not in gravid does) and cestodes with praziquantel. Treatment of leptospirosis with doxycycline administered 4.29-5.36 mg once a week is useful prophylactically, although for insurance of effectiveness, 10 mg/kg for 5 days is recommended. An identical dosage is recommended for the treatment of rickettsia. African trypanosomosis infection, following diagnosis of parasites in a blood smear, can be treated with a variety of antiprotozoal drugs like diminazene diaceturate at 3.5 mg/kg for 5 days. Leishmaniasis is treated at the same dose. Staphylococcosis is treated with amoxycillian trihydrate at 5 mg/kg 3 times a day for 7 days. Helminthosis is treated with broad-spectrum deworming solution. Coccidiosis is treated with cotrimoxazole at 100 mg/kg daily for 3 days. Non-steroidal anti-inflammatories are administered to combat secondary bacterial infection after viral invasion.

Cerebral Amyloid-Beta Protein Accumulation with Aging in Cotton-Top Tamarins: A Model of Early Alzheimer's Disease?

Alzheimer's disease (AD) is the most common progressive form of dementia in the elderly. Two major neuropathological hallmarks of AD include cerebral deposition of amyloid-beta protein (Abeta) into plaques and blood vessels, and the presence of neurofibrillary tangles in brain. In addition, activated microglia and reactive astrocytes are often associated with plaques and tangles. Numerous other proteins are associated with plaques in human AD brain, including Apo E and ubiquitin. The amyloid precursor protein and its shorter fragment, Abeta, are homologous between humans and non-human primates. Cerebral Abeta deposition has been reported previously for rhesus monkeys, vervets, squirrel monkeys, marmosets, lemurs, cynomologous monkeys, chimpanzees, and orangutans. Here we report, for the first time, age-related neuropathological changes in cotton-top tamarins (CTT, Saguinus oedipus), an endangered non-human primate native to the rainforests of Colombia and Costa Rica. Typical lifespan is 13-14 years of age in the wild and 15-20+ years in captivity. We performed detailed immunohistochemical analyses of Abeta deposition and associated pathogenesis in archived brain sections from 36 tamarins ranging in age from 6-21 years. Abeta plaque deposition was observed in 16 of the 20 oldest tamarins (>12 years). Plaques contained mainly Abeta42, and in the oldest animals, were associated with reactive astrocytes, activated microglia, Apo E, and ubiquitin-positive dystrophic neurites, similar to human plaques. Vascular Abeta was detected in 14 of the 20 aged tamarins; Abeta42 preceded Abeta40 deposition. Phospho-tau labeled dystrophic neurites and tangles, typically present in human AD, were absent in the tamarins. In conclusion, tamarins may represent a model of early AD pathology.

Anti-Predator Behavior of Captive-Reared and Wild Juvenile Spiny Lobster (Jasus edwardsii)

Early juvenile lobsters reared in captivity may loose anti-predator behaviors displayed by their wild counterparts. To test this hypothesis in juvenile spiny lobsters (Jasus edwardsii), we conducted a series of experiments in which recently settled pueruli were reared in captivity under differing levels of predation risk. After one year in captivity, these lobsters were exposed to a predator in a tank or released into the wild to assess their ability to recognize and respond to predation. We found that lobsters raised without predators significantly reduced their movement activity outside shelters when subsequently introduced to a predator compared with juveniles raised with predators (F1,45 = 4.33, p < 0.05). This apparent over-compensation may be necessary for lobsters to learn the appropriate anti-predator response. Lobsters raised without predators and released into the wild displayed the same types of behaviors as resident wild lobsters. Released lobsters spent more time defending and fighting amongst themselves than the wild lobsters (G = 13.006 > χ2 0.05,2 = 9.488), but they displayed the appropriate anti-predator responses when approached or attacked by a predator. Our results show that juvenile spiny lobsters habituate to the absence of a predator when reared in captivity for long periods, but display an innate ability to recognize and effectively respond to predators when encountered in a hatchery environment or in the wild.

Urolitiase em lobo guara (Chrysocyon brachyurus): Avaliação de quatro casos clínicos em cativeiro

Foram estudados quatro casos de urolitíase em lobos guarás (Chrysocyon brachyurus), que ocorreram no período de 1989 a 2004, de animais mantidos em cativeiro. Os casos clínicos ocorreram em quatro machos adultos. O tempo de cativeiro para a manifestação da doença nos animais variou de dois meses a 10 anos. Os principais sintomas clínicos apresentados foram distensão abdominal, infecções recorrentes do trato urinário, dor à palpação abdominal, dificuldade em urinar, polaciúria, hematúria, anorexia, desidratação e tenesmo urinário com evolução para anúria em decorrência da obstrução da uretra por cálculos. Ao exame radiológico detectou-se distenção da bexiga e a presença de inúmero urólitos radiopacos no lúmen do órgão. As análises difratométricas dos urólitos revelaram que eles eram compostos de Pirofostato Ácido de Cálcio e Fosfato Básico de Manganês Hidratado (n=1)) e Fosfato de Amônio Magnésio Hidratado com traços de Fosfato de Potássio e Cálcio (n=1). A microscopia eletrônica revelou que os urólitos eram formados por cristais, com predominância dos minerais de fósforo, potássio e magnésio (n=2) em sua composição. O presente estudo demonstrou, de forma inédita, a ocorrência de urolitíase associada a urólitos de composição mineral a base de fosfato, potássio e magnésio, em lobos guarás cativos. Até então, só foram documentados casos de urolitíase em lobos guarás relacionados à cistina. As medidas terapêuticas da urolitíase envolvem manejo nutricional adequado, utilização de medicamentos e, em alguns casos, cirurgias específicas. O diagnóstico e tratamento das doenças que acometem animais silvestres em cativeiro são de extrema importância para a manutenção e reprodução dessas espécies, visando à sua conservação no meio ambiente.

Seasonal variation in feed intake under constant temperature and natural photoperiod in the green sea urchin (Strongylocentrotus droebachiensis)

Feed intake, body growth, and gonad growth of adult green sea urchin Strongylocentrotus droebachiensis were investigated at a constant temperature (10 °C) and a simulated natural photoperiod (70 °N) for 848 days. Three size groups of sea urchins with an initial test diameter of 30–40 mm (small, S, N=32), 40–50 mm (medium, M, N=36), and 50–60 mm (large, L, N=32) were cultured individually and fed a formulated moist feed in excess. During the first period of the trial, the test diameter (days 0–560), the feed conversion ratio (days 0–560), and the gonad index (GI, days 0 and 560) were recorded. The feed intake (FI) was registered during the entire period (848 days) and varied strongly with season for all size groups. Hence, the FI was significantly higher in summer (0.5–0.6 g per animal per day) than in winter (0.2–0.3 g per animal per day). The test diameter, on the other hand, increased in a linear manner with no apparent seasonality. The S group displayed the fastest increase in test diameter and the highest ingestion rare followed by size groups M and L. By day 560, the GI had reached 33–35% irrespective of size group, which is the highest GI-value reported for this species. Overall, our findings demonstrate that the feed intake of the adult green sea urchins is strongly linked to season at a constant temperature, and that the seasonality in feed intake is maintained for years in captivity.

In the Lands of the Christians: Arabic Travel Writing in the Seventeenth Century (review)

In the Lands of the Christians: Arabic Travel Writing in the Seventeenth Century (review)

Histological study of the effects of treatment with gonadotropin-releasing hormone agonist (GnRHa) on the reproductive maturation of captive-reared Atlantic bluefin tuna (Thunnus thynnus L.)

The effects of gonadotropin-releasing hormone agonist (GnRHa) administration on the gonads of 66 Atlantic bluefin tuna (Thunnus thynnus L.) reared in floating cages (La Azohía, Murcia, Spain) were evaluated using histological analyses. During two consecutive reproductive seasons (June–July 2004 and 2005), about half of the fish in each cage were administered a GnRHa implant using a spear gun, without being anesthetized or physically restrained, and were sacrificed for sampling 2–8 d later. Rearing for 1–3 years in captivity did not prevent vitellogenesis and oocyte growth, since yolk granule formation and oocyte diameter of fully vitellogenic oocytes were similar to wild fish. However, a lower gonad size and number of vitellogenic oocytes were observed compared to wild spawners. None of the 14 untreated Controls had oocytes at final oocyte maturation (FOM) at the time of sampling and postovulatory follicles (POFs) were observed only in three of them. In addition, a higher volume fraction of atretic oocytes was observed in untreated Controls when compared to the wild or GnRHa-treated fish, indicating a shut-down of reproductive activity at this time. On the contrary, all GnRHa-treated females had oocytes at FOM and/or POFs, with the exception of two fully atretic individuals. In the males, no differences in testicular histology were observed between GnRHa-treated and Control fish, and individuals were at early or late spermatogenesis. The study indicates that wild-caught Atlantic bluefin tuna reared in captivity undergo vitellogenesis and spermatogenesis, but females have a low capacity for spontaneous FOM and ovulation, whereas GnRHa treatment is effective in inducing multiple cycles of FOM and ovulation.

First results on spawning, larval rearing and growth of the wedge sole (Dicologoglossa cuneata) in captivity, a candidate species for aquaculture

The wedge sole is a target species in the fisheries of the Gulf of Cadiz (Spain). Having reared them to commercial size, we have studied reproduction and breeding in captivity of the wedge sole in this work here. The breeders adapt easily to captivity, and they can spawn in less than 1 year in captivity. The relative fecundity is relatively high, 1.06–2.33 · 106 eggs kg−1 per spawning season (mean 1.6 ± 0.1). Larval SGR is high, 7.2 ± 0.2% day−1 (range 5.8–9.1), similar to other cultured flatfish species. In 1 year, some individuals reach market size and can release eggs, registering SGRs of 1.39–1.66% day−1 (mean 1.56 ± 0.01). This species presents some very different characteristics with respect to other farmed flatfishes (turbot, halibut and Senegal sole, mainly), so that it is necessary to develop new techniques to optimise its cultivation. In the present work, the first results are presented on the biology of the wedge sole in captivity.