1 Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz, B.C. S., Mexico, 23090. 2 Southwest Fisheries Science Center, NOAA Fisheries Service, La Jolla, CA, USA 92037. 3 Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA 92093-0203. 4 Universidad Autónoma de Baja California Sur México, Dep. Biología Marina, La Paz, U.A.B.C.S., Mexico 23081. 5 The Institute of Environmental and Human Health Texas Tech University and TTU, Health Sciences Center, Lubbock, Texas, USA 79416. 6 Ocean Alliance, Lincoln, MA, USA 01773. * Corresponding author: Nadia T. Rubio-Cisneros – Scripps Institution of Oceanography, University of California. San Diego, La Jolla, CA, USA 92037. E-mail: nrubio@ucsd.edu. 7 Mangels, K. and Gerrodette, T. (1994) Report of cetacean sightings during a marine mammal survey in the eastern Pacific Ocean and the Gulf of California aboard the NOAA ships Mc Arthur and David Starr Jordan, July 28-November 6, 1993. NOAA TM-NMFSSWFSC-211, US Department of Commerce, Seattle, WA, USA. 8 Godard, C., Clark, R., Harper, C., Mesnick, S., Moore, M., Payne, R., Rubio-Cisneros, N. and Stegeman, J. (2003) CYP1A1 expression in sperm whale Physeter macrocephalus skin biopsies show site but not sex differences. Page 60 in Abstracts, 15th Biennial conference on the Biology of Marine Mammals, 14-19 December, Greensboro, NC, USA. GENETIC SEX DETERMINATION SUPPORTS THE GULF OF CALIFORNIA AS AN IMPORTANT HABITAT FOR MALE AND FEMALE SPERM WHALES (PHYSETER MACROCEPHALUS)

We challenge the hypothesis that fin whales use a magnetic sense to guide migration by testing for associations between geophysical parameters and the positions where fin whales were observed over the continental shelf off the northeastern United States. Monte Carlo simulations estimated the probability that the distribution of fin whale sighting was random with respect to bottom depth, bottom slope and the intensity and gradient of the geomagnetic field. The simulations demonstrated no overall association of sighting positions with any of these four geophysical parameters. Analysis of the data by season, however, demonstrated statistically reliable associations of sighting positions with areas of low geomagnetic intensity and gradient in winter and fall, respectively, but no association of sighting positions with bathymetric parameters in any season. An attempt to focus on migrating animals by excluding those observed feeding confirmed the associations of sighting positions with low geomagnetic intensity and gradient in winter and fall, respectively, and revealed additional associations with low geomagnetic gradients in winter and spring. These results are consistent with the hypothesis that fin whales, and perhaps other mysticete species, possess a magnetic sense that they use to guide migration.

Restriction endonuclease analysis of mitochondrial DNA purified from 11 south Atlantic (Capetown, South Africa) and 12 north Pacific (San Diego, USA) albacore tuna (Thunnus alalunga) revealed no restriction sites which could distinguish an Atlantic from a Pacific albacore. Although restriction site variation was found within the pooled sample, variants were found only in single fish. These results suggest either recent isolation of Atlantic and Pacific albacore or, more likely, at least a small amount of migration between the two ocean basins.

ABSTRACT We tested the hypothesis that cetaceans use weak anomalies in the geomagnetic field as cues for orientation, navigation and/or piloting. Using the positions of 212 stranding events of live animals in the Smithsonian compilation which fall within the boundaries of the USGS East-Coast Aeromagnetic Survey, we found that there are highly significant tendencies for cetaceans to beach themselves near coastal locations with local magnetic minima. Monte-Carlo simulations confirm the significance of these effects. These results suggest that cetaceans have a magnetic sensory system comparable to that in other migratory and homing animals, and predict that the magnetic topography and in particular the marine magnetic lineations may play an important role in guiding long-distance migration. The ‘ map’ sense of migratory animals may therefore be largely based on a simple strategy of following paths of local magnetic minima and avoiding magnetic gradients.

Although the presence of magnetite in their tissues is correlated with the ability of different species to detect magnetic fields, proof that the magnetite is involved in magnetoreception has not yet been provided. Using the approach employed to localize and isolate magnetic particles in the yellowfin tuna, we found that single-domain magnetite occurs in chains of particles in tissue contained within the dermethmoid cartilage of adult chinook salmon,Oncorhynchus tshawytscha. The particles are present in sufficient numbers to provide the adult fish with a very sensitive magnetoreceptor system. Magnetite in the chinook can be correlated with responses to magnetic fields in a congeneric species, the sockeye salmon. Based on the presence of the chains of particles, we propose behavioral experiments that exploit the responses of sockeye salmon fry to magnetic fields to test explicit predictions of the ferromagnetic magnetoreception hypothesis.

Restriction endonuclease analysis of mitochondrial DNA indicated a surprisingly high degree of genetic similarity between skipjack tuna (Katsuwonus pelamis) from the Atlantic and Pacific Oceans. The present results (1983) support the findings of previous morphological and electrophoretic studies. Evidently, since the uplift of the Panamá land bridge about 3.1 million years ago, there has been continued genetic contact between Atlantic and Pacific skipjack tuna, presumably via the Southern Ocean.

Single-domain magnetite crystals have been isolated and characterized from tissue located in a sinus within the dermethmoid bone of the skull of the yellowfin tuna, Thunnus albacares . Their chemical composition, narrow size distribution, and distinctive crystal morphology indicate that these crystals are biochemical precipitates. Experiments on the interaction between particles reveal the organization of the particles in situ and suggest a possible form for candidate magnetoreceptor organelles. The consistent localization of such particles with similar arrangement within the dermethmoids of this and other pelagic fishes suggests that the ethmoid region is a possible location for a vertebrate magnetic sense organ.

Macrophage polarization refers to how macrophages have been activated at a given point in space and time. Polarization is not fixed, as macrophages are sufficiently plastic to integrate multiple signals, such as those from microbes, damaged tissues, and ...Read More

recreational fishermen who troll off Hawaii's Kona coast. The problem is now a major economic concern of the night handline fishery of the same island. This highly effective, cost efficient industry, found only in Hawaii and in the Philippines (Yuen, 1979), would be an excellent candidate for fishery development in export-poor Pacific island na­ tions if the burn problem could be controlled. Whatever the causes of burn, we suspect that the problem is exacerbated by the limited chilling facilities found aboard most night handline and recreational fishing boats. In Hawaii, traditional marketing practices delay the discovery of burn. A typical fish changes hands at least twice in the first 48 hours after death. The fisherman consigns his catch to a wholesaler who then either sells it locally or ships it to a more distant market. If the fish is sold locally, the fish is butchered

Compositions for inhibiting anomalous deposition and mobilization of calcium phosphates in animal tissue, comprising an effective amount of certain polyphosphonates as herein defined, and a pharmaceutical carrier; and a method for treating or preventing conditions involving pathological calcification and hard tissue demineralization in an animal comprising administering to such animal said compositions.

We show that electrical stimulation of the midbrain of restrained and sedated skipjack tuna (Katsuwonus pelamis) produces coordinated locomotory activity. Therefore, our preparation is a viable alternative for creating normal swimming movements which can be closely controlled by the experimentalist, and demonstrates that a midbrain “locomotory center” is present in skipjack tuna, as in other teleosts.

To determine their capacity for thermoregulation, yellowfin tuna, Thunnus albacares, were subjected to a series of 12-h periods at Ta's of 20, 25, and 30 C. Muscle temperature, measured with an ultrasonic transmitter attached to the fish, and swim speed were simultaneously monitored. No relationship was found between speed and muscle temperature, although metabolic heat production is inexorably linked to the former. Because both direct and inverse muscle temperature/heat production relationships were observed, and because physical (as opposed to physiological) explanations for our data can be discounted, we hypothesize yellowfin tuna are capable of some type of central nervous system (CNS)-mediated physiological thermoregulation.

To test the hypothesis that white muscle fibre portions of the myotomes are used at sustainable swimming speeds, skipjack tuna, Katsuwonus pelamis, were forced to swim against various current velocities in a water tunnel while electrical activity of the red and white muscle fibres was simultaneously recorded. Eight fish were tested, five fish graded white muscle fibres into activity at swimming speeds above their minimum hydrostatic equilibrium speed, but well below the estimated maximum sustainable swimming speed of skipjack tuna. Three other fish showed white muscle fibre activity at minimum swimming speeds, a possibly abnormal condition.

Because tunas possess countercurrent vascular pathways serving the trunk musculature, metabolic heat is retained, and muscle temperatures can considerably exceed that of the surrounding water (+1° to +21°C). And because tunas have this excess, it is reasonable to suppose they have some means of controlling its magnitude. Tunas must contend with two exigencies which can perturb body temperature: changes in water temperature and, in contrast to non-thermoconserving fish, changes in activity. Both can be met by adaptive change in excess muscle temperature. If this could be accomplished in the absence of changes in environmental temperature or activity level, this would constitute physiological thermoregulation. If excess muscle temperature cannot be altered sufficiently to acceptable levels, more favorable environmental temperatures must be sought or activity levels changed. We would consider this behavioral thermoregulation. High sustained swim speeds, characteristic of the continuously swimming tunas, require special consideration. Heat production is proportional to approximately the cube of swim speed. In order to maintain a slight temperature excess at basal swim speeds (1–2 lengths/sec), and yet not overheat during sustained high speed swimming (>4 lengths/sec), mechanisms are required to conserve heat under the former conditions and to dissipate it effectively under the latter. In this report, we review published observations other investigators have interpreted as physiological thermoregulation in tunas, describe recent findings in our laboratory, and suggest some possible thermoregulatory mechanisms.