Follicle cell processes: a shark thing?

Follicle cell processes (FCP) are identified in two species of carcharhinid shark (Selachii) but are absent in the little skate Leucoraja erinacea (Batoidea). This suggests that FCPs are either a unique structure that evolved in selachians or were lost by the batoids after their divergence, some 280 mya . The presence of FCPs in the selachians would be consistent with the evolution of large oocytes in this group of animals.     

Longitudinal Assessment of Immature-to-Adult Ratios in Two Groups of Costa Rican Alouatta palliata

We used immature-to-adult female ratios (IFR), which indicate replacement rates, to assess changes in and viabilities of nonhuman primate groups and populations. Heltne et al. (1975) concluded that the howling monkey (Alouatta palliata) population at La Pacifica (Guanacaste, Costa Rica) was declining, as the IFR was <1.5, the ratio thought needed for a sustainable population. Our population surveys of 1984, 1991, and 1998 revealed that the number of monkeys in the population was stable, but the number of groups had increased and mean group size decreased. To examine these group-level changes, we present the IFR and immature-to-adult (IAR) ratios for La Pacifica Groups 2 and 18, which we have studied longitudinally for 18 and 10 years, respectively. Group 2 was larger than Group 18, but both groups showed similar mean IFRs for the study periods. The mean IFR for each group exceeded the population IFR. The annual IFRs varied more in the smaller group than in the larger group, and the IARs for these groups varied more than the IFRs did. All annual IFRs in the groups were below the hypothesized critical value of 1.5. Given these group and population values, we examined this critical IFR value with respect to mantled howler life history characteristics, particularly interbirth intervals and juvenile emigration, both of which preclude ratios 1.5, and compared the La Pacifica mantled howler population ratios with those of other populations. Group size, in conjunction with these ratios, might be more predictive of sustainable groups and populations.     

不同生态品种群桃果实糖酸及其组分含量分析

以涵盖我国6个生态品种群的118份桃地方品种为试验材料,对其糖酸组分进行全面分析,以明确不同桃区果实糖酸组分分布特性,为优异糖酸种质筛选提供依据。应用斐林试剂测定果实可溶性糖含量;应用Na OH测定果实可滴定酸含量;应用高效液相色谱(HPLC)技术测定果实糖组分,离子色谱技术测定果实酸组分。结果表明:西北高旱桃区的品种,主要以可滴定酸、柠檬酸、苹果酸、总酸表现出较高的分布水平,蔗糖、总糖、糖酸比、固酸比表现出较低的分布水平;华北平原及长江流域桃区的品种,主要以糖酸比、固酸比表现出较高的分布水平,可滴定酸、柠檬酸、苹果酸、总酸表现出较低的分布水平;云贵高原桃区的品种,主要以可溶性糖、蔗糖、总糖表现出较高的分布水平,糖酸比、固酸比表现出较低的分布水平;华南亚热带桃区的品种,主要以蔗糖、总糖、糖酸比、固酸比表现出较高的分布水平,可滴定酸、柠檬酸、苹果酸表现出较低的分布水平;东北高寒桃区的品种,主要以果糖表现出较高的分布水平,糖酸比、固酸比表现出较低的分布水平。6个生态品种群的品种,果糖所占比例以长江流域桃区最高,葡萄糖以西北高旱桃区最高,山梨醇以华南亚热带桃区最高,而东北高寒桃区最低,蔗糖所占比例在不同生态区无明显差别。柠檬酸所占比例以长江流域桃区最高,而华南亚热带桃区最低,奎宁酸所占比例以华南亚热带桃区最高,琥珀酸、苹果酸所占比例在不同生态品种群间无明显差异。     

Periodic shedding and replacement of venomous caudal spines,with special reference to South American freshwater stingrays,Potamotrygon spp.

Synopsis The number of venomous caudal spines and their length and position relative to one another were determined in seven species of South American freshwater rays (Potamotrygonidae) and eight marine or euryhaline species of four families from the Caribbean Coast of South and Central America. Most species have two visible spines at certain stages in the shedding-replacement cycle and only one visible spine at other stages (following shedding). If we include the embryological beginnings of the spines before they erupt and become visible, the spine counts of most rays are actually 2 rather than 1 or 2. Since most species apparently follow this pattern, spine counts are of little use in distinguishing between species except in the relatively few that may have only one, or no spines. Eight captive Potamotrygon specimens maintained in simulated tropical temperature conditions over 12 months showed periodic shedding and replacement of spines. The molts were biannual for a given ray but annual for a given spine. They alternated between two spine loci and their cycles were approximately six months out of phase with each other. Recent studies on Dasyatis sabina by others report only one molt per year, with replacement spines forming always posterior to the primary spine rather than alternating between posterior and anterior. Supernumerary spines (counts of more than two, up to five) are also discussed, as are counts of one and zero.     

丹参水溶性成分的研究概况

丹参是一种传统中药,但其水溶性成分的研究是近年才展开的.本文概述了丹参水溶性部分的化学成分、提取分离、含量测定和药理研究的最新进展.     

Population survey of macaques in northern Sulawesi

A field survey of 25 sites in Sulawesi Utara (north Sulawesi) in 1987 and 1988 found macaques in 16 of these sites. The most viable population of Macaca nigra was found in the Tangkoko reserve at an estimated density of 76.2 monkeys/km², which is less than one-third the abundance reported in the late 1970s by the MacKinnons. The adjacent reserves of Batuangus and Duasudara had only 22 monkeys/km², yielding a population estimate for these three contiguous reserves of only 3,655 individuals. Maccaca nigrescens were found in the central and western portions of Dumoga-Bone National Park in densities of 15.5 and 16.4 monkeys/km², significantly below the density of 27/km² reported by the MacKinnons. The more peripheral areas of Dumoga-Bone had only 8.15 monkeys/km², yielding a population estimate of M. nigrescens in Dumoga-Bone of less than 34,000. Our total population estimate for M. nigra and M. nigrescens combined is less than 50,000 individuals, which is considerably below that reported in recent litreture. M. hecki were observed in only two locations, Tangale and Panua Reserves, at low densities of 3.3 to 5.2 monkeys/km², suggesting its range and abundance have declined since the observations of Groves (pp. 84–124 in THE MACAQUES: STUDIES IN ECOLOGY, BEHAVIOR AND EVOLUTION. D. G. Lindburg, ed. New York, Van Nostrand Reinhold, 1980). Several factors have contributed to population decline in these species: habitat shrinkage, increasing human population pressure, and drought conditions. Group sizes were significantly smaller in our study than in previous ones, and we found a shortage of juveniles and infants.     

东北虎血液成分的测定与分析

用氰化高铁血红蛋白法、改良纽鲍氏计算板法、显微测量法、低渗ＮａＣｌ试管法、微量毛细吸管离心法、血细胞计算板法和瑞特氏染色三区计数法,分别测得和算出８只东北虎血液中血红蛋白含量１３１±７．５ｇ／Ｌ、红细胞数７．１１±Ｏ．５３×１０１２／Ｌ、红细胞直径５．５８（４．６２—６．５５）μｍ、红细胞渗透脆性０．６０６±０．０６５—０．４３０±０．０４５％、红细胞压积容量３８．１±２．６８％、白细胞总数２３．３±７．５×１０９／Ｌ、嗜中性白细胞５７．９％、淋巴细胞３５．６％、单核细胞３．５％、嗜酸性粒细胞１．８％、嗜硷性粒细胞＜１％、平均红细胞体积５３．６±２．７５ｆＬ、平均红细胞血红蛋白含量１７．９±１．２５Ｐｇ、平均每个红细胞血红蛋白分子数１５８９±１１０×１０５个、平均红细胞血红蛋白浓度３３．５±２．７％;用全自动凯氏定氮法测定并计算得出血清总蛋白含量７３．６±１２．６ｇ／Ｌ、血清白蛋白含量４６．５±３．２％及血清球蛋白含量２７．１±１３．１ｇ／Ｌ。上述各项结果为保护东北虎提供了难得而有意义的生理参考值。     

Skeletal form and growth in Acropora aspera (Dana) from the Pulau Seribu,Indonesia

Linear extension and calcium carbonate accretion were measured in the branching coral Acropora aspera (Dana) from shallow-water sites around Pulau Pari, Pulau Seribu, Indonesia, during both wet and dry monsoon periods. Skeletal density and corallite form were also monitored in specimens collected from sites, variously affected by wave energy resulting from the monsoonal influence. Although the reversing monsoon appeared to exert the greatest effect on skeleton growth (by influencing temperature and possibly number of “sun-hours”) wave energy was also shown to affect skeletal extension, skeletal accretion, and skeletal density. The scale of differences between growth rate measurements was greatest for weight of skeleton accreted between monsoon period (8-fold), followed by between site differences (maximum 3-fold during west monsoon) and finally between station differences (maximum 3-fold during west monsoon at an outer reef flat and reef edge station). Skeletal extension did not appear to be as sensitive to the reversing monsoon influence as skeletal accretion.