| 1. |
- De Facci, Monica, et al.
(författare)
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Flagellar sensilla of the eusocial gall-inducing thrips Kladothrips intermedius and its kleptoparasite, Koptothrips dyskritus (Thysanoptera: Phlaeothripinae)
- 2011
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Ingår i: Arthropod Structure & Development. - : Elsevier BV. - 1467-8039. ; 40, s. 495-508
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Tidskriftsartikel (refereegranskat)abstract
- Insect antennal flagella host a multitude of sensory organs fulfilling different functions. Chemoreception, for example, is essential for insects in many contexts. Both olfaction and contact chemoreception are involved in host-plant selection, as well as in the integrity of insect societies, especially for nestmate recognition. Kladothrips intermedius is a eusocial gall-inducing thrips with two castes: dispersers and soldiers. Koptothrips dyskritus is a specialist in invading Kl. intermedius galls, killing the occupants, and thereby gaining the food and shelter offered by galls. In this study, we compared the morphology and ultrastructure of the flagellar sensilla of Kl. intermedius and Ko. dyskritus via scanning and transmission electron microscopy in order to facilitate future investigations of their sensory ecology, with an emphasis on chemical ecology. The two species show a very similar sensillar array. There are a few mechanosensory trichoid and a second type of mechanosensory sensilla, thermo-hygroreceptive sensilla, olfactory single-walled basiconic and double-walled coeloconic sensilla as well as contact chemoreceptive chaetic sensilla. The latter are sexually dimorphic in Kl. intermedius. Dispersers and soldiers of Kl. intermedius do not present noteworthy morphological differences, but the ultrastructural investigations revealed that soldiers have fewer ORNs, possibly an adaptation to their gall-cloistered lifestyle.
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| 2. |
- Ekerholm, Mattias, et al.
(författare)
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Primer and short-range releaser pheromone properties of premolt female urine from the shore crab Carcinus maenas
- 2005
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 1573-1561 .- 0098-0331. ; 31:8, s. 1845-1864
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Tidskriftsartikel (refereegranskat)abstract
- The European shore crab Carcinus maenas is considered to rely on a female pheromone when mating. Evidence, however, is scarce on how the urine pheromone in itself affects males. We investigated male primer and releaser responses to female pheromones with methods that minimized effects from females, delivering female urine either as a pump-generated plume or deposited on a polyurethane sponge. We delivered the pheromone at different concentrations in far, near, and close/contact range to get a picture of how distance affects behavioral response. Our results show that substances in premolt female urine (PMU) function as primer and potent short-range releaser pheromones. Based on the olfactometer and sponge tests, we conclude that PMU stimulus in itself is sufficient to elicit increased search and mating-specific behaviors such as posing, posing search, cradle carrying, and stroking. Pheromone concentrations do not seem to be important for attenuating search and posing as long as the level is above a certain threshold concentration. Instead, pheromone levels seem to play a role in male acceptance of females, recruiting more males to respond, and generating better responses with increasing concentration.
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| 3. |
- Elofsson, Rolf, et al.
(författare)
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Compound eyes of some deep-sea and fiord crustaceans
- 1977
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Ingår i: Acta Zoologica. - : Wiley. - 0001-7272 .- 1463-6395. ; 58, s. 169-177
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Tidskriftsartikel (refereegranskat)abstract
- The compound eyes of the deep-sea mysid Boreomysis scyphops and the two mysid species Amblyops abbreviata and Pseudomma affine, which are indigenous to deep fiords in Norway, have been investigated. The eye stalks are greatly transformed, but contain hypertrophied retinas. The ommatidia of all three species lack a dioptric apparatus, possessing only retinular cells, which are arranged in a cylinder-like fashion. Folds from the retinular cells project into the “cylinder” and are covered with microvilli. The arrangement is explained functionally by an increase in the photopigment-bearing surface as an adaptation to low-light intensities. The orderly arrangement of microvilli in most arthropod compound eyes has been lost, and the arrangement is thus multidirectional in these mysids. With the photopigment dipoles arranged along the microvillar axis, the disorderly arrangement of microvilli signifies a more efficient capture of non-polarized light. It is concluded that the mysid compound eyes show adaptations to low-light intensities probably acquired during the species' evolutionary descent into deep-sea habitats. Amblyops abbreviata and Pseudomma affine, belonging to genera with entirely transformed eyes and with an ultrastructure less “normal” than that of Boreomysis scyphops are believed to be earlier descendants into the deep-sea habitats than the latter species, which belongs to a genus in which most of the species have well-developed eyes.
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| 4. |
- Elofsson, Rolf, et al.
(författare)
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Correlation of ultrastructure and chemical composition of crustacean chromatophore pigment
- 1973
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Ingår i: Journal of Ultrastructure Research. - 0022-5320. ; 44, s. 421-429
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Tidskriftsartikel (refereegranskat)abstract
- Chromatophores, with chemically identified pigment, from the body and eyes of crustaceans were investigated ultrastructurally. Red carotenoid-, black ommochrome-, and white pteridine-containing chromatophores were found to have pigment granules of different morphological appearance.
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| 5. |
- Elofsson, Rolf, et al.
(författare)
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The juxtaposed compound eye and organ of Bellonci in Haploops tubicola (Crustacea:Amphipoda)- the fine structure of the organ of Bellonci.
- 1980
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Ingår i: Zoomorphology. - 0720-213X. ; 96, s. 255-262
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Tidskriftsartikel (refereegranskat)abstract
- The amphipod species Haploops tubicola has an unusual compound eye that is divided into three separate parts, each with one common cuticular lens. The dorso-frontal eyepair has, in addition to the lens, a so-called vitreous body, which is constructed like a dioptric lens and is inserted in the ray-path. The ‘vitreous body’ is actually — and for which evidence is presented — a secretory product formed in the intercellular spaces of the organ of Bellonci. Histochemical analysis has shown that the secretion is strongly PAS-positive and lacks glycogen.
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| 6. |
- Garm, A, et al.
(författare)
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Role of maxilla 2 and its setae during feeding in the shrimp Palaemon adspersus (Crustacea : Decapoda)
- 2003
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Ingår i: Biological Bulletin. - 0006-3185. ; 204:2, s. 126-137
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Tidskriftsartikel (refereegranskat)abstract
- The movements of the basis of maxilla 2 in Palaemon adspersus were examined using macro-video recordings, and the morphology of its setae was examined using both scanning and transmission electron microscopy. The basis of maxilla 2 performs stereotypical movements in the latero-medial plane and gently touches the food with a frequency of 3-5 Hz. The medial rim of the basis of maxilla 2 carries three types of seta. Type 1 is serrate, type 2 and 3 are serrulate, and type 2 has a prominent terminal pore. Type 2 is innervated by 18-25 sensory cells whose cilia protrude through the terminal pore and are in direct contact with the external environment. The structure of type 2 setae indicates that they are mainly gustatory, although still bimodal due to their innervation by presumed chemosensory and mechanosensory neurons. Distally, the three types of setae have a complex arrangement of the cuticle involving water-filled canals, which may serve to improve flexibility. Type I and 3 setae have fewer sensory cells (4-9) but probably also have a bimodal sensory function. The function of type I setae is probably to protect type 2 setae, while type 3 setae might serve to groom the ventral side of the basis of maxilla 1.
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| 7. |
- Hallberg, Eric, et al.
(författare)
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An ascothoracid compound eye (Crustacea)
- 1985
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Ingår i: Sarsia. - : Informa UK Limited. - 0036-4827. ; 70, s. 167-171
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Tidskriftsartikel (refereegranskat)abstract
- The ultrastructure of the compound eye of an ascothoracid larva — the only known occurrence of compound eyes in the Ascothoracida — is described. The ommatidia of apposition type consist of a crystalline cone composed of three cells and up to six retinular cells. Poor fixation of the scarce material allows no safe judgement about the number of retinular cells and the nature of two distal cells surrounding the crystalline cones. The structure of these compound eyes most closely resembles the cirriped compound eye.
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| 8. |
- Hallberg, Eric, et al.
(författare)
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Classification of amphipod compound eyes- the fine structure of the ommatidial units (Crustacea, Amphipoda)
- 1980
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Ingår i: Zoomorphology. - 0720-213X. ; 94, s. 279-306
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Tidskriftsartikel (refereegranskat)abstract
- The ultrastructure of the compound eyes of 13 amphipod species has been investigated. An amphipod type of compound eye can be characterized by the constellation and consistency of a number of morphological features, most of which are also found in other compound eyes. The amphipod eye falls into four sub-categories (types). The ampeliscid type has a tripartite aberrant lens eye; the lysianassid type has a reduced or no dioptric apparatus and a hypertrophied rhabdom; the hyperid type possesses a large number of ommatidial units with long crystalline cones and dark instead of reflecting accessory pigment; and finally, the gammarid type can be interpreted as a generalized amphipod type. The lysianassid type is adapted to low light intensities and demonstrates convergent development with the compound eyes of other deep-sea crustaceans. The ampeliscid type is more similar to the gammarid type. The type characterization of the amphipod compound eye might well serve as a basis and incentive for functional studies also revealing adaptational mechanisms.
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