General ecology of the cassiduloid urchin Cassidulus caribbearum
General ecology of the cassiduloid urchin Cassidulus caribbearum
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卡西杜类海胆 Cassidulus caribbearum 的一般生态学
DOI：
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发表时间：
1978
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通讯作者：
W. Gladfelter
中科院分区：
文献类型：
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作者：
W. Gladfelter
Cassidulus caribbearum是棘足目Cassiduloida的代表，分布在加勒比海东部波多黎各海岸岛屿上高密度的局部种群中（高达100 m-2）。这些小海胆（可达35毫米）是穴居动物，主要生活在有粗砂底的浅水地区。运动是通过双轴波实现的，从腹部侧面的大的可移动的刺的前面传到后面；这种机制在棘足类动物中是独一无二的。挖掘是最有效的沙粒尺寸最接近的环境（0至1 φ）。这些海胆是有选择性的沉积物捕食者，它们摄取的基质颗粒主要在0到1φ的大小范围内。个体或多或少连续摄取沙子；在实验室中，沙子完全通过肠道平均需要6小时。亚里斯多德的灯笼存在于幼体（测试长度<1.0毫米），但在海胆达到5.0毫米的测试长度之前被吸收。肠道在大体形态上与蛛形肠相似。耗氧量与湿重相似的其他热带棘足类动物相当。加勒比海海胆会在产蛋刺中孵出大的（350 μm）蛋黄蛋，孵化期为10到12天，这段时间小海胆会爬到沙滩上。连续的、重叠的海胆会产生，因此经常在一个海胆上出现两个不同发育阶段的海胆。单个海胆可以连续孵化长达4个月或更长时间。在全年中，超过18毫米的个体中至少有50%的个体在孵蛋，在仲夏期间最高可达85%。所有抽样地区的人口性别比均大于5比1。没有发现原雄性两性的证据。从标记的个体和种群样本中位数大小的增加来衡量，生长速度在0.5到1.0毫米之间。死亡主要是由于腹足动物黑醋栗结节的捕食，尽管偶尔的，偶发性死亡是由物理因素造成的，如强风暴潮。
Cassidulus caribbearum, a representative of the echinoid order Cassiduloida, occurs in localized populations of high densities (up to 100 m-2) among the islands of the Puerto Rico bank in the eastern Caribbean Sea. These small (up to 35 mm) urchins are burrowers, principally in shallow-water areas with coarse sand bottom. Locomotion is achieved by ditaxic waves, passing from the front to the rear of large movable spines on the lateral portions of the ventral surface; this mechanism is unique among echinoids. Digging was most effective in sand grain sizes most closely approximating those of the environment (0 to 1ϕ). These urchins are somewhat selective deposit feeders, which ingest substrate particles primarily in the size range 0 to 1ϕ. Individuals ingest sand more or less continuously; complete passage of sand through the gut takes an average of 6 h in the laboratory. Aristotle's lantern is present in young juveniles (test length <1.0 mm), but is resorbed before the urchins reach a test length of 5.0 mm. The gut shows similarities in gross morphology to the spatangoid gut. Oxygen consumption is comparable to that of other tropical echinoids of similar wet weight. C. caribbearum broods its large (350 μm) yolky eggs among the aboral spines for 10 to 12 days, at which time young urchins crawl off into the sand. Successive, overlapping broods are produced, so that frequently two broods of different developmental stages are present on a single urchin. Single urchins may brood continuously for up to 4 months or more. Throughout the year, at least 50% of all individuals over 18 mm were found brooding, with a maximum of 85% of all individuals brooding in mid-summer. The sex ratio of the population in all areas sampled was greater than 5 females to 1 male. No evidence of protandric hermaphroditism was found. Growth rate, measured from tagged indivuduals and from increase in median size in population samples, was between 0.5 and 1.0 mm month-1. Mortality was due primarily to predation by the gastropod Cassis tuberosa, although occasional, episodic mortality was caused by physical factors such as heavy storm swells.