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The genus Squamidium, a group of mosses with a tropical to subtropical American-African distribution, consists of two sections and seven species (prior to this study 27 species were recognized): sect. Squamidium (S. leucotrichum, S. livens, S. isocladum, S. nigricans, S. brasiliense) and sect. Macrosquamidium (S. macrocarpum and S. diversicoma). Twenty-four names are treated as syn. nov., three are provisionally excluded pending an examination of their types, and one new combination is made: Orthostichopsis pilotrichelloides (Sehnem) Allen & Crosby. Section Squamidium ist characterized by immersed capsules, stolon leaves with entire margins, and a relatively high basal membrane. Section Macrosquamidium is characterized by exserted capsules, stolon leaves with sharply recurved marginal teeth, and a relatively low basal membrane. The genus is retained in the Meteoriaceae. Within the Meteoriaceae Squamidium, is most closely related to Zelotmeteorium from which it differs only by its lack of squarrose-recurved leaves and its more well-developed alar cells. Squamidium, which in the absence of sporophytes has been confused consistently with Orthostichopsis, is separated from that genus on the basis of its lack of pseudoparaphyllia, weaker costae, lack of a distinct region of reddish cells across the leaf base, and strongly decurrent alar cells.
A survey of the freshwater fishes of the Sepik River system of northern Papua New Guinea was undertaken by the authors between 1978 and 1985 with the use of gill nets and rotenone, and also by monitoring catches at local villages and markets. We also include records of past expeditions, namely that of the Dutch naturalist Gjellerup in 1910 and the yacht Illyria in 1929. The total known freshwater fauna as reported herein consists of 57 species in 35 genera and 23 families. The fauna is typical of other sections of New Guinea and northern Australia in that it is dominated by catfishes (Ariidae and Plotosidae), rainbow fishes (Melanotaeniidae), gudgeons (Eleotrididae) and gobies (Gobiidae) which collectively comprise 57 percent of the total species. With the exception of 22 widely distributed species that are frequently estuarine dwellers and are confined to the lower Sepik, the fishes are strongly endemic, either to the Sepik-Ramu drainages (which interconnect during Doods), or the "intermontane trough" composed of the combined Markham, Ramu, Sepik, and Mamberamo systems. Individual accounts, including brief descriptions and information pertaining to habitat, distribution and biology are included for each species. In addition illustrations are provided for many of the endemic species.
The North Arnerican species of the genus Cremastocheilus are reviewed. These belong to 5 subgenera, Macropodina, Trinodea, Anatinodia, Mymcotonus, and Cremastocheilus. Taxonomie changes are: She inclusion of Crernastocheilus nitens and C. chapini in the subgenus Cremastocheilus rather than Myrmecotonus. Also Anatinodia is elevated to subgeneric status. A key to the subgenera is provided, as is a key to the species of the 5 subgenera, recognizing that the 35 species in the subgenus Cremastocheilus are in need of revision. A critical review of the host records, geographic distribution, and ecology of the Tribe Crernastocheilini (Family Scarabaeidae. subfamily Cetoniinae) is provided. This contains enormous numbers of new records for both the genera Genuchinus and CremastocheiLus both from the literature and from the extensive field work that is reported here for the first time. A Summary of the host records is presented in tabular form. This table shows the association of all species of Cremastocheilus with ants as adults and the larvae either associated with the vegetable material of the ant nests or with vegetable material in rodent burrows. Genuchinus is shown to be a general predator on soft bodied insects while the other genera of the Cremastocheilini are associated with plants, particularly bromeliads. A detailed study of the external morphology and sexual dimorphism of the genera Genuchinus and Crernastocheilus is presented. All species of Cremastocheilus can be sexed with the naked eye by the difference in the shapes of the abdominal terminal Segments, wherein males have the posterior border of the last ventral abdominal segment either straight or slightly bowed, while females have this border broadly rounded. There are other microscopic sexual differences in the structure of the legs. The rest of the external morphology is also presented, particularly from the point of view of adaptations to either a predaceous or rnyrmecophilous existente. Particularly adapted for predation are the pointed maxillae which are used for piercing prey. Particularly adapted for myrmecophily are the mentum, the maxillae, the generally thick exoskeleton, trichomes on both the anterior and posterior angles of the pronotum, the elytra, and the legs (which are adapted to the nest substrate of the host ant nests. Exocrine glands are described for Genuchinus ineptus and at least 1 species of each of the 5 subgenera of Cremastocheilus. In general, there are no gland cells nor glandular areas in Genuchinuc that are comparable to those of Cremastocheilus. The gland cells and glandular areas are quite extensive andvariable arnong species of Cremastocheilus. The frontal gland of some Cremastocheilus (strongly developed in C. castaneus and the C. canaliculatus species group, but weakly developed in the C. wheeleri species group) is described for the first time. Because these glands are not found in Genuchinus ineptuc, a species with general predatory habits, it is thought that these play a role, as yet unknown, in interactions with ants. The life cycles of the subgenera of Cremastocheilus are described. The general life cycle entails adult beetles eclosing in ant nests during the summer and then undertaking dispersal flights. The adults then enter ant nests and ovenivinter there, eating ant larvae during the Winter. Another dispersal flight occurs in the spring during which the adults mate and enter ant nests again. The females then lay eggs and the adults die. The eggs hatch and the larvae spend 3 instars feeding upon vegetable material in the nests. The lmae then pupate in typical scarabaeine earthen cells made of fecal material and soil. These eclose in the summer and the cycle is repeated. Variation from species to species is largely in the timing. Leaving the nest in late Summer, mating seems to be triggered by rainfall in all the species studied. Mating of C. (Macropodina) beameri takes place in rodent burrows. Males seem attracted to females from a distance but the mechanism of this remains obscure. In the subgenus Trinodia, mating takes place on sandy washes or roadsides where females land. In the subgenus Myrmecotonus, maüng also takes place in sandy areas. In C. (Cremastocheilus) mating takes place on sand bars along rivers in the southeastern U.S. and in sand dunes in northeastern U.S. The femaies dig down into the sand. Males locate these places by some unknown mechanism and then dig down to copulate with the females. Field experiments showed unequivocaily that males dig only into areas occupied by females. No sex-specific Sex attractant glands have been located in females so far. Dispersal to ant nests occurs after mating except for C. (Macropodina) beameri which lays its eggs in the rodent burrows and then probably disperses to ant nests. Beetle activity going in and out of nests was studied using wire hardware cloth screens over entrances to Mynnecocystus nests. The mesh size was such that the ants could move freely in or out but the beetles got stuck by their thoraces. The direction then could be interpreted by the direction in which they got stuck. By this method, C. stathamae was shown to leave nests from 23 June to 1 September with a peak on 6 July, just after the beginning of the summer rains. Beetles entered nests from June 23 to August 3, however 39% entered on July 16, probably pulsed by the leaving time which was correlated with the rains. Life cycle timing: C. (Macropodina) develop in the nests of Wood rats (Neotoma sp.]. Females lay about 40 eggs each. The 3 larval instars to pupation take about 1 month. Pupae are found from late August to weil into September. In other subgenera as well, larvae are found in parts of the nest devoid of ants, The timing is similar in all the subgenera found with ants. Mortality factors: While ants attack Cremastocheilus adults, there is no evidence that they are ever killed by ants nor is there evidence that ants kill larvae nor hard earthen pupae cases which protect the pupae. During dispersal fiights and mating, the adults are exposed to predation and evidence is presented that shows predation by horned toads, spiders, magpies, and tiger beetles. Probably most mortality occurs in the larval and pupd stages where the beetles are attacked by internal parasites and fungus. Further rnortality is caused by limitation of the food supply during the larval stage. Reentering nests: Females of C. (Macropodina) beameri select specific rodent and other burrows, attract males for rnating. and then enter the burrow for oviposition. C. stathamae are carried into the ants nests from as far away as 25ft. The beetles appear to land spontaneously after flying randomly over M. depilis nesting areas. Then the wander about waiting for the ants to carry them into the nests. Cremastocheilus hirsutus fly low over the ground searching for Pogonomyrrnex barbatus nests, land. and move straight for the nest entrances which they enter unhindered. Among all species, the ants frequently eject beetles but the net rnovement is in. Ants frequently attacked Cremastocheilus in laboratory observation nests when they were introduced. These attacks seldom resulted in the death of the beetles and the beetles were eventually ignored. When the beetles entered brood chambers, where they fed upon larvae, they were mostly ignored and even licked assiduously by the ants. A principle defensive behavior by the beetles is feigning death (letisimulation). The beetles give off an unpleasant "dead fish odor when collected in the I field. Experiments show that this substance functions to fend off some predators but further experiments indicated that these substances were ineffective against both ants and kangaroo rats. Experiments with various species of Cremastocheilus adults indicate that the adults eat only ant larvae. The beetles will eat larvae of non-host ants but show preferences for the larvae of their normal hosts. Under the same experimental conditions. Genuchinus ineptus adults will feed on a variety of insect adults and larvae. Field experiments on the function of trichome secretions did not indicate that they function to attract ants at a distance nor are they involved in worker acceptance. Laboratory experiments in which areas with a high concentration of gland cells were presented to ants showed that no ants were attracted. Laboratory introduction of Cremastocheilus hamisii adults into Fomica schau.si nests yielded many interactions including ants licking the anterior pronotal angles, the mentum area where the frontal glands empty and a carina over the eye with a dense pad of short setae. These are areas of concentration of gland cells and these are the first observations of licking by ants in specific sites containing exocrine glands. Radioisotope experiments showed food exchange among ants but never from ants to beetles. Other experiments showed that ants can pick up radioactivity from the beetles without feeding on trichome secretions. Evolutionary pathways: Adult Cremastocheilini probably followed the evolutionary route from adult predation on soft bodied insects to specialized feeding upon ant brood and the subsequent development of the beetle larvae in vegetable material in the ant colonies. Thus Genuchininseptus makes a logical outgroup in that they are general predators probably feeding mostly on Diptera larvae associated with Sotol plants in the field. The rnajor evolutionary step taken by Cremastocheiluswas to specialize on ant brood. Then the species radiated into ant colonies inhabiting southwestem North Arnenca. Most of the ant hosts invaded have quantities of vegetable material in their nests sufficient to support several developing scarab larvae. Host colonies are large, contain accessible brood, and are usually dominant foragers Evidence supports the idea that the species of Cremastocheilus have differentes in behavior and morphology that reflect adaptation to the behavioral ecology of different species of ants rather than different evolutionary levels of integration into ant colonies.
Interaction between species in a marine ecosy stem is described by expressions for food consumption and grazing mortality which are consistent with each other and with the Beverlon and Holt model of the population dynamics ofindividual species. A model of primary production is introduced in order to make possible an account of nutricnt circlliation (as examplified by phosphorus) within and nutrient flow through the system. It is demonstrated in an application to North Sea fishencs that recent changes in total yield can be described in some detail under the terms of the model as a function of fishing mortality alone. The composition of the North Sea fauna in the virgin state is discussed and also the conditions under which total yield could be increased above the 1970 level.
Aeration in higher plants
(1979)
Until recently, up to thirteen specics of the scincid genus, Scincus, were recognized, but examination of some 590 individuals frorn a wide range of localities suggests that only three or four are valid. Of these, S. mitranus is confined to eastern and southern Arabia and S. hemprichii probably to southwest Arabia. The remaining forms constitute the S. scincus complex, which may consist in North Africa of two largely allopatric species, S. scincus and S. albifasciatus, although evidence for this is not conclusive. The S. scincus complex is represented in southwest Asia by two forms : S. scincus meccensis in southern Jordan, northwest and west Arabia and S. s. conirostris in southern and eastern Arabia, Iraq and southwest Iran. Scincus appears to have evolved Erom a primitive scincine, very similar to members of the Eumeces schneideri group, especially E. (schneideri) algariensis; it does not seem to be directly related to the sympatric genus Scincopus. Within Scincus, the S. scincus complex is the least specialized component of the genus and both S. rnitranus and S. hemprechii may have been independently derived from it, or from a closely related form. Possibly the whole range of the genus was once occupied by a S. scincus-like species and its distribution was subsequently restricted by the onset of less desertic conditions leaving reduced populations in North Africa, southwest Arabia and southeast Arabia that gave rise to the S. scincus complex, S. hemprichii and S. mitranus respectively. A renewed expansion of arid areas could then have enabled the S. scincus complex to invade southwest Asia. Some of the characters of its most eastern subspecies, S. s. conirostris, may have arisen, or been maintained, by character displacement through contact with S. mitranus.