A profile of the Monterey squid fleet in 1992

There were approximately 20 vessels active in the 1992 Monterey Bay squid fishery. The size of the fleet has not changed since the early 1970's when 15 to 20 vessels participated in the fishery. Since 1977, eleven steel hulled vessels have been added to the fleet, replacing smaller wooden hulled vessels that were in use during the 1960's. The hold capacity of the new fleet remains about 800 tons, because the new larger vessels replaced small vessels that used lighters (20 - 25 ton capacity non-motorized barges). Purse seines were legalized in 1989 and have replaced lamparas which were in use during the 1960'S and 1970's. Seines used in the squid fishery are small and shallow, ranging from 120 to 200 fm in length with most less than 25 fm deep. Crew size has been reduced nearly 50% by the addition of net reels, power blocks, submersible fish pumps, and vacuum pumps used for unloading at dockside. In the 1970's flasher type fathometers were used by the fleet and few vessels had navigational aids. Today most of the fleet have sonar, radar, and loran C. Three vessels carry global positioning systems. In 1988 squid attracting lights were legalized and the entire fleet used lights during the 1992 season. (21pp.

Potential Use of a Serpin from Arabidopsis for Pest Control

Although genetically modified (GM) plants expressing toxins from Bacillus thuringiensis (Bt) protect agricultural crops against lepidopteran and coleopteran pests, field-evolved resistance to Bt toxins has been reported for populations of several lepidopteran species. Moreover, some important agricultural pests, like phloem-feeding insects, are not susceptible to Bt crops. Complementary pest control strategies are therefore necessary to assure that the benefits provided by those insect-resistant transgenic plants are not compromised and to target those pests that are not susceptible. Experimental GM plants producing plant protease inhibitors have been shown to confer resistance against a wide range of agricultural pests. In this study we assessed the potential of AtSerpin1, a serpin from Arabidopsis thaliana (L). Heynh., for pest control. In vitro assays were conducted with a wide range of pests that rely mainly on either serine or cysteine proteases for digestion and also with three non-target organisms occurring in agricultural crops. AtSerpin1 inhibited proteases from all pest and non-target species assayed. Subsequently, the cotton leafworm Spodoptera littoralis Boisduval and the pea aphid Acyrthosiphon pisum (Harris) were fed on artificial diets containing AtSerpin1, and S. littoralis was also fed on transgenic Arabidopsis plants overproducing AtSerpin1. AtSerpin1 supplied in the artificial diet or by transgenic plants reduced the growth of S. littoralis larvae by 65% and 38%, respectively, relative to controls. Nymphs of A. pisum exposed to diets containing AtSerpin1 suffered high mortality levels (LC50 = 637 µg ml−1). The results indicate that AtSerpin1 is a good candidate for exploitation in pest control

Classification and Selection of Cellular Materials in Mechanical Design: Engineering and Biomimetic Approaches

Recent developments in design and manufacturing have greatly expanded the design space for functional part production by enabling control of structural details at small scales to inform behavior at the whole-structure level. This can be achieved with cellular materials, such as honeycombs, foams and lattices. Designing structures with cellular materials involves answering an important question: What is the optimum unit cell for the application of interest? There is currently no classification framework that describes the spectrum of cellular materials, and no methodology to guide the designer in selecting among the infinite list of possibilities. In this paper, we first review traditional engineering methods currently in use for selecting cellular materials in design. We then develop a classification scheme for the different types of cellular materials, dividing them into three levels of design decisions: tessellation, element type and connectivity. We demonstrate how a biomimetic approach helps a designer make decisions at all three levels. The scope of this paper is limited to the structural domain, but the methodology developed here can be extended to the design of components in thermal, fluid, optical and other areas. A deeper purpose of this paper is to demonstrate how traditional methods in design can be combined with a biomimetic approach

Laboratory Observations of Reproduction in the Deep-Water Zoarcids Lycodes cortezianus and Lycodapus mandibularis (Teleostei: Zoarcidae).

v. ill. 23 cm.QuarterlyThe first observations of reproduction and associated behaviors in captive bigfin eelpout, Lycodes cortezianus, and pallid eelpout, Lycodapus mandibularis, are reported here. One Lycodes cortezianus pair produced 13 transparent and negatively buoyant eggs that were approximately 6 mm in diameter. These were laid on a hydroid-covered rock. The development period was about 7 months, and the young that emerged were approximately 2 cm in total length. An additional captive pair also exhibited mating behavior as the male repeatedly nudged the female and the pair produced a burrow under a sponge; however the male died before any mating. Two gravid female Lycodapus mandibularis were captured and laid between 23 and 46 eggs that were about 4 mm in diameter. These were released on the sandy substrate after the females moved the sand about the tank, and the eggs were negatively buoyant. These eggs were all unfertilized. Additional burrowing behavior was observed from other captive individuals, but no eggs were subsequently produced. Taken together, our observations suggest that burrowing or use of other protective structures is a reproductive behavior of central importance to zoarcids. Contrary to some earlier hypotheses, even midwater species likely return to the sediment to burrow and/or deposit eggs. This behavior means that field data regarding reproduction in this family will continue to be difficult to obtain, and the contribution of further study in laboratory situations should not be underestimated

Prey capture in long-jawed butterflyfishes (Chaetodontidae): the functional basis of novel feeding habits

Several species of butterflyfishes (Chaetodontidae) possess extremely elongate jaws, and feed mostly by probing the benthos and biting off pieces of attached invertebrates. In contrast, Forcipiger longirostris, the longest-jawed chaetodontid, exhibits a novel pattern of prey use, feeding almost exclusively on small caridean shrimp, a mobile and highly elusive prey type that lives within the structure of coral reefs. We explored the functional basis of this novel pattern of prey use by comparing prey capture kinematics in this and four other butterflyfish species, including two other species that possess elongate jaws. High speed video recordings of feeding events on live adult brine shrimp were analyzed from individuals of five species: Forcipiger longirostris, F. flavissimus, Chelmon rostratus, Heniochus acuminatus, and Chaetodon xanthurus. We focused on a comparison among species of the relative contribution of “suction”, measured as the amount of movement of the prey toward the predator’s mouth, and “ram”, measured as the distance moved by the predator toward the prey during the strike. All five species utilized a combination of suction and ram while feeding on brine shrimp. The contribution of suction did not differ significantly among species. However, F. longirostris exhibited a ram contribution to the strike that was more than twice that seen in any of the other species, permitting this species to initiate strikes from the greatest initial predator-prey distance. F. longirostris is known to possess a major structural novelty in the feeding mechanism that permits anterior movement of the entire jaw apparatus. The ability of this species to feed successfully on elusive prey appears to be related to exceptional jaw protrusion, resulting in greater use of ram during prey capture. This ability to protrude long, slender jaws toward the prey may allow it to move the jaws without detection within close enough proximity of the prey to then permit the effective use of suction. The use of extensive ram in this manner by small-mouthed fishes may be more widespread than previously thought

Food Habits of Spotted Sand Bass (Paralabrax maculatofasciatus, Serranidae) from Bahia De Los Angeles, Baja California

In this study, we compare feeding habits of spotted sand bass, Par- alabrax maculatofasciatus, between two sampling periods, fall 1992 and spring 1994, characterized by different local oceanographic and environmental condi- tions, at Bahia de Los Angeles, Baja California, Mexico. Fish, ophiuroids, and brachyuran crabs dominated sand bass diet in fall 1992, contrasted with mysids in 1994. Diet was more diverse in 1992 than in 1994, and higher in prey evenness and lower in index of specialization and prey dominance, indicating a few items had a large impact on the diet in 1994. Among size classes within each year sampled, the largest fish consumed the most mobile prey items. The spotted sand bass\u27 ability to utilize such a wide variety of prey appears to be the key to its success in varying habitats

Plasticity in feeding selectivity and trophic structure of kelp forest associated fishes from northern Chile Plasticidad en la selección de alimento y estructura trófica de los peces asociados a bosques de macroalgas pardas del norte de Chile

One of the primary ways in which species interact with their environment is through foraging; thereby directly consuming some fraction of their surrounding habitat. The habitat itself, in turn, may dictate the types of foraging opportunities that are available to the inhabitants. To investigate the relationship between habitat availability and diet composition of habitat-associated fishes, we estimated the relative abundance of the potential sessile and mobile prey items and the diet of the fish species assemblage associated to kelp forest. Specifically, diet and feeding selectivity of the kelp-forest associated fish assemblage were determined by calculating Manly's alpha selectivity index. We determined the diet of kelp forest associated fishes and their foraging behavior by comparing prey availability with those items present in the stomachs of fishes captured by gill net and spear gun. We calculated the degree of dietary overlap among fishes from four locations along the northern coast of Chile. Results indicate that utilization of prey by predators is predominantly affected by potential prey availability. With the exception of the two carnivorous species such as Pinguipes chilensis (Valenciennes, 1883) and Paralabrax humeralis (Cuvier & Valenciennes, 1828), whose diet did not change among sites, all other kelp-associated fishes changed their dietary habitats to consistent with the availability of local resources. Benthic resources changed among the different study sites, which led to differing diets even in the same species from different locations. Eleven of the 12 kelp forest fishes also showed some selectively for benthic prey. We conclude that the ability of fishes to be plastic in their feeding preference and, therefore, partition the benthic resources may set adaptations to co-exist in a dynamic environment such as kelp forest.<br>Una de las principales formas en que las especies interactúan con su medio ambiente es a través de la alimentación, consumiendo directamente una fracción de los componentes del hábitat circundante. El propio hábitat, a su vez, puede determinar la conducta de forrajeo y los tipos de alimentación de sus depredadores. Para investigar la relación entre la disponibilidad de alimento y la composición de la dieta de los peces asociados a hábitat dominados por macroalgas pardas, se estimó la abundancia de las presas potenciales tanto especies sésiles como móviles y se comparó con la dieta de las especies de los peces en cuatro diferentes sitios de la costa del norte de Chile. Se determinó la dieta de los peces y su plasticidad alimentaria mediante la comparación entre la disponibilidad de presas con los ítemes presentes en los estómagos de los peces que fueron capturados por de red de enmalle y arpón de mano. Además se calculó el índice de selectividad alfa de Manly y el grado de sobreposición de la dieta de los peces costeros. Los resultados muestran que la utilización de las presas por los depredadores es afectada principalmente por la disponibilidad de presas potenciales. La mayoría de los peces asociados a las macroalgas difieren en su dieta en consonancia con la disponibilidad de los recursos a escalas locales, con la excepción de dos especies carnívoras tales como Pinguipes chilensis (Valenciennes, 1883) y Paralabrax humeralis (Cuvier & Valenciennes, 1828), cuya dieta no cambió entre los sitios estudiados. Las diferencias en la dieta de las especies son explicadas por los cambios en los recursos bentónicos que varían entre los sitios de estudio. Once de las 12 especies de peces asociados a los bosques de macroalgas pardas mostraron algún grado de selectividad de presas de origen bentónico. Se concluye que la habilidad de los peces de cambiar sus preferencias de alimentación y, por tanto, la partición de los recursos bentónicos puede obedecer a las adaptaciones para coexistir en un ambiente dinámico como aquel dominado por bosques de macroalgas pardas

Modulation of prey capture kinematics in the cheeklined wrasse Oxycheilinus digrammus (Teleostei: Labridae)

The ability to modulate prey capture behaviors is of interest to organismal biologists as it suggests that predators can perceive features of the prey and select suitable behaviors from an available repertoire to successfully capture the item. Thus, behavior may be as important a trait as morphology in determining an organism’s diet. Using high-speed video, we measured prey capture kinematics in three cheeklined wrasse, Oxycheilinus digrammus. We studied the effects of three experimental prey treatments: live fish, dead prawn suspended in the water column, and dead prawn pieces anchored to the substrate in a clip. Live prey elicited significantly more rapid strikes than dead prey suspended in the water column, and the head of the predator was expanded to significantly larger maxima. These changes in prey capture kinematics suggest the generation of more inertial suction. With greater expansion of the head, more water can be accelerated into the buccal cavity. The attached prey treatment elicited strikes as rapid as those on live prey. We suggest that the kinematics of rapid strikes on attached prey are indicative of attempts to use suction to detach the prey item. More rapid expansion of the buccal or mouth cavity should lead to higher velocities of water entering the mouth and therefore to enhanced suction. Further modulation in response to the attached prey item, such as clipping or wrenching behaviors, was not observed

Evolution and mechanics of long jaws in butterflyfishes (Family Chaetodontidae)

We analyzed the functional morphology and evolution of the long jaws found in several butterflyfishes. We used a conservative reanalysis of an existing morphological dataset to generate a phylogeny that guided our selection of seven short- and long-jawed taxa in which to investigate the functional anatomy of the head and jaws: Chaetodon xanthurus, Prognathodes falcifer (formerly Chaetodon falcifer), Chelmon rostratus, Heniochus acuminatus, Johnrandallia nigrirostris, Forcipiger flavissimus, and F. longirostris. We used manipulations of fresh, preserved, and cleared and stained specimens to develop mechanical diagrams of how the jaws might be protruded or depressed. Species differed based on the number of joints within the suspensorium. We used high-speed video analysis of five of the seven species (C. xanthurus, Chel. rostratus, H. acuminatus, F. flavissimus, and F. longirostris) to test our predictions based on the mechanical diagrams: two suspensorial joints should facilitate purely anteriorly directed protrusion of the lower jaw, one joint should allow less anterior protrusion and result in more depression of the lower jaw, and no joints in the suspensorium should constrain the lower jaw to simple ventral rotation around the jaw joint, as seen in generalized perciform fishes. We found that the longest-jawed species, F. longirostris, was able to protrude its jaws in a predominantly anterior direction and further than any other species. This was achieved with little input from cranial elevation, the principal input for other known lower jaw protruders, and is hypothesized to be facilitated by separate modifications to the sternohyoideus mechanism and to the adductor arcus palatini muscle. In F. longirostris the adductor arcus palatini muscle has fibers oriented anteroposteriorly rather than medial-laterally, as seen in most other perciforms and in the other butterflyfish studied. These fibers are oriented such that they could rotate the ventral portion of the quadrate anteriorly, thus projecting the lower jaw anteriorly. The intermediate species lack modification of the adductor arcus palatini and do not protrude their jaws as far (in the case of F. flavissimus) or in a purely anterior fashion (in the case of Chel. rostratus). The short-jawed species both exhibit only ventral rotation of the lower jaw, despite the fact that H. acuminatus is closely related to Forcipiger