The functional-morphological adaptive strategy of digestive organs of decapodiform cephalopods

The digestive organs in decapodiform cephalopod species morphologically vary byindividual lifestyle. We examined the following six species of adult decapodiformescephalopods representing different habitats: Todarodes pacificus, Loligobleekeri, Loligo edulis, Wataseniascintillans (pelagic), Sepia lycidas and Euprymnamorsei (benthic). L. bleekeri and L. edulispossess a bursiform cecal sac connected to the cecum. Pelagic species have a singledigestive gland smaller than in benthic species. T. pacificus has an ovaldigestive gland larger than that of L. bleekeri and L.edulis, which possess withered-looking and smaller digestive glands. Incontrast, the digestive glands in benthic species are paired. S. lycidasand E. morsei have well-developed and larger digestive glands than thoseof the pelagic species. Well-developed digestive duct appendages are found in benthicspecies. In qualification of the mass of digestive organs, pelagic species have smallerstomachs, digestive glands and digestive ducts’ appendages than benthic species. Becausepelagic species need to swim, they may possess smaller stomachs and larger cecums for morerapid digestion. A smaller digestive gland may have the advantage of reducing the bodyweight in pelagic species for rapid swimming. In contrast, since benthic species require alonger time for digestion than pelagic species, they compact more food in their stomachsand absorb nutrients via more organs, such as the digestive grand and digestive ductappendages, in addition to cecum.     

Positional strategy of trunk muscles among aquatic,semi-aquatic and terrestrial species in Urodela

Clarification of the trunk structure in Urodela is important in understanding the locomotive evolution of basal tetrapods. The components of the muscular trunk wall among Urodela using different modes of locomotion were compared. Since the whole trunk may be used for swimming and the effect of limbs may be small in the more aquatic species, they showed smaller differences in the trunk muscles among anterior, middle and posterior sections of the trunk. By contrast, in the more terrestrial species, the dorsal and abdominal muscles are larger in the middle section than those in the anterior and posterior sections. High compressive stresses occur in the supporting limbs and their insertion at the trunk on the ventral side, and spread from the forelimbs along the back to the supporting hindlimbs on the dorsal side. Tensile stresses occur in the middle ventral part. The components of the trunk muscles among the three sections may reflect differences in stresses occurring in the trunk of the more terrestrial species. The findings also suggest that in the middle section, larger dorsal muscles for stiffening the back to maintain posture and larger abdominal muscles are responsible for balancing the body weight while it is supported by the limbs in the more terrestrial species.     

Effects of Latent Infection of Stock Plants and Abundance of Thrips on the Occurrence of <Emphasis Type="Italic">Tomato spotted wilt virus </Emphasis>in Chrysanthemum Fields

DAS-ELISA proved to be reliable enough to detect a latent infection by Tomato spotted wilt virus (TSWV) in asymptomatic stock plants of chrysanthemum. A high density of Frankliniella occidentalis, the predominant vector, in the presence of latently infected stock plants resulted in a high incidence of disease in the chrysanthemum production field. The incidence of disease was low when the vector thrips were not abundant in spite of the presence of latently infected stock plants. These results suggest that an infestation of the vector thrips causes severe secondary spread of TSWV originating from latently infected stock plants in chrysanthemum production fields. Received 27 July 2001/ Accepted in revised form 27 November 2001     

Molecular Characterization of <Emphasis Type="Italic">Bean yellow mosaic virus </Emphasis>from Vegetatively Propagated Dwarf <Emphasis Type="Italic">Gentiana </Emphasis>Plants

The causative virus (isolate No. 4) of gentian (Gentiana spp.) mosaic, which had been identified previously as Clover yellow vein virus (C1YVV) on the basis of host range and serological reactions, was re-identified as Bean yellow mosaic virus (BYMV) on the basis of the nucleotide sequences of the gene for the coat protein (CP) and the 3′-noncoding region, as well as the predicted amino acid sequence of CP. Received 16 April 2002/ Accepted in revised form 19 June 2002     

Effects of pre-shipping marbofloxacin administration on fever and blood properties in healthy Thoroughbreds transported a long distance

The present study evaluated the effects of single-dose marbofloxacin in protecting horses against fever associated with transportation using 48 healthy Thoroughbreds. All horses were premedicated with interferon-α (0.5 U/kg, sublingually, every 24 hr) for 2 days before transportation and on the day of transportation. Horses were randomly assigned to receive marbofloxacin (2 mg/kg, IV, once; MRFX group), enrofloxacin (5 mg/kg, IV, once; ERFX group) or saline (0.9% NaCl) solution (10 ml, IV, once; control group) ≤1 hr before being transportation. Each group contained 16 horses (8 males, 8 females). Horses were transported 1,210 km using commercial vans over the course of approximately 26 hr. Clinical examinations and hematologic analyses were performed on all horses both before and after transportation. Post-transportation neutrophil to lymphocyte ratios were significantly lower in horses in the MRFX group compared with the control horses. The serum amyloid A levels were significantly lower in horses in the MRFX group and ERFX group compared with the control horses. Regarding the post-transportation rectal temperatures, fever was detected in 0 horses and 1 horse in the MRFX and ERFX groups, respectively, whereas fevers exceeding 39.1°C were detected in 2 horses in the control group. Additionally, the number of essential post-transportation treatments provided by veterinarians was reduced 3-fold in the MRFX and ERFX groups compared with the saline group. MRFX provided ERFX-like protection against fever associated with long-distance transportation, yielding significantly better protection than saline. Administration of MRFX just before transportation deserves a further study for efficacy in preventing horse fever associated with transportation.     

Effects of a combination of hinokitiol (β‐thujaplicin) and an organic acid mixture on ruminal fermentation in heifers fed a high‐grain diet

This study evaluated the effects of hinokitiol (a natural antibacterial compound extracted from Thujopsis dolabrata var. hondai) and an organic acid mixture (citrate content 50%) on ruminal fermentation. Antibacterial properties were examined by measuring minimal inhibitory concentration. Hinokitiol at 1.56 µg/mL or an organic acid mixture at 1600 µg/mL inhibited Streptococcus bovis growth. The combination of 0.78 µg/mL hinokitiol and 200 µg/mL of an organic acid mixture also inhibited S. bovis growth. Both hinokitiol and the hinokitiol and an organic acid mixture combination showed strong antibacterial properties on Gram‐positive bacteria such as S. bovis, but relatively weak antibacterial activities on Gram‐negative bacteria such as Megasphaera elsdenii. Three ruminally cannulated heifers were fed a bloat‐producing diet containing barley, pelleted alfalfa meal, soybean meal and salt without long‐cut roughage to investigate the ruminal characteristics in vivo. Feeding to heifers a bloat‐producing diet containing 7.8 mg/kg hinokitiol and 0.2% of an organic acid mixture significantly decreased the increase in stable ingesta volume. Hinokitiol or an organic acid mixture did not affect ruminal volatile fatty acids, protozoa and bacteria. These results suggest that a combination of hinokitiol and an organic acid mixture might reduce frothy bloat in cattle fed high‐grain diets.