-
海
洋
生
物
群
落
中
的
< br>种
间
关
系
第一节
种间食物关系
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种间关系是指不同物种种群之间的相互作用。
一、食物关系的生态学意义
二、海洋动物食性的基本类型
三、海洋动物对食物的选择性
四、海洋动物食性的特化
五、海洋动物食性的转化
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本章教学目的及基本要求：
通过本
章的学习，
掌握生物群落中种间关系的类型、
种间食物关系
的生态学意义、捕食者与被食者的辨证关系；种间竞争的基本原理、
生态位的基本概念、生态位分化的主要方式。
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本章重点、难点：
重点：种间食物关系；种间竞争与生态分离。
难点：有关模型的生物学意义。
第一节
种间关系的类型
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一、捕食（营养关系）
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二、竞争
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三、互利
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四、共栖（偏利）
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五、寄生
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六、偏害
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七、中性现象
1
、捕食（营养关系）
一种生物以另一种生物为食物（营养）。
2
、竞争
同种或异种的两个或更多个个体间
发生对于资源（栖息空间、
食物）的争夺。
牡蛎<
/p>
——
藤壶；
罗非鱼的领域性
3
、互利
两种生物以某种方式生活在一起，对双方都有利。
珊瑚礁大型鱼类
——
鱼
“
医生
”
虎鮋
——
水螅
（转移栖息场所和提供伪装）
双锯鱼
——
海葵
（吸引饵料生物并分享）
鳑鲏
——
河蚌
蚌的呼吸水流给鳑鲏卵供氧，鳑鲏体表作为稚贝附着基
4
、共栖（偏利）
两种生
物以某种方式生活在一起，对一方有利，对另一方
无害。
鲨鱼
——
领港鱼；
鲨鱼
——
鮣鱼；
军舰鱼
——
葡萄牙军舰水母
海参
——
潜鱼
5
、寄生
通常是一物种对另一物种构成有害影响。
6
、偏害
（
1
）
两种生物以某种方式生活在一起，
对一方有害，
对另一方无影响。
（
2
）甲物种通过乙物种对丙物种产生危害
，乙物种不受影响。
贝毒危害人类。
7
、中性现象
彼此互不影响。空间和食物的利用不产生竞争
第二节
种间食物关系
一、种间食物关系的生态学意义
1.
个体水平上：
食物是动物需要的营养物质的主要来源，
也是动物有机体与外
界环境之间最普遍的联系。
2.
种群水平上：
食物联系直接或间接地决定种间矛盾斗争的发展和变化。
这种
食物关系往往起到
:
优存劣汰
种群数量调节
共同进化（协同进化）。
协同进化（
coevolution)
3.
群落水平上：
食物联系是影响群落的结构与动态的重要调节因素。
捕食者与被食者
有
一定程度相互依赖的辩证关系，这种食物关系是维持群落稳定性的一个
重要机制。
4.
生态系统水平上：
食物联系是生态系统物流和能流的主要途径，
通过食物联系，
生态系统
生物能够有规律地依次利用从
自然界得到的物质和能量，这些物质和有
规律地循环与流动，是生态系统赖以生存与发展
的基本条件。
一、捕食作用
1
捕食者与猎物的协同进化
协同进化（
coevolution)
Red Queen Hypothesis
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The
on coevolution.
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The original
idea is that coevolution could lead to situations
for which the probability of
extinction
is relatively constant over millions of years (Van
Valen 1973).
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The gist of the idea is that, in
tightly coevolved interactions, evolutionary
change by one
species (e.g., a prey or
host) could lead to extinction of other species
(e.g. a predator or
parasite), and that
the probability of such changes might be
reasonably independent of
species age.
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Van Valen named
the idea
species had to
data.)
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The other idea is that coevolution,
particularly between hosts and parasites,
could lead to sustained oscillations in
genotype frequencies (Fig. 1).
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This idea forms
the core for one of the leading hypotheses for the
persistence of
sexual reproduction see
Bell 1982). In species where asexual reproduction
is
possible (as in many plants and
invertebrates), coevolutionary interactions with
parasites may select for sexual
reproduction in hosts as a way to reduce the risk
of infection in offspring.
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There have been
many important cont
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ributors to the Red Queen hypothesis as
it applies to sex. W.D. Hamilton and
John Jaenike were among the earliest
pioneers of the idea.
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Figure 1. Red
Queen dynamics: results from a computer simulation
for host-parasite
coevolution.
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The
blue line gives the frequency of one host
genotype;
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the
red line gives the frequency of the parasite
genotype that can infect it.
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Note that both
genotypes oscillate over time, as if they were
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The
model assumes that hosts have self-nonself
recognition systems, which can detect
foreign organisms. The model also
assumes that hosts and parasites both reproduce
sexually.
Red
Queen hypothesis
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The phrase
Looking Glass
(Carroll 1872). In Alice's dream about the looking
glass house,
she first finds that
things appear left-to-right, as if shown in a
mirror. She then
finds that chess
pieces are alive. She will later encounter several
of these pieces
(most notably the Red
Queen), after she leaves the looking glass house
to see
the garden.
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Alice decides
that it would be easier to see the garden if she
first climbs the hill,
to which there
appears to be a very straight path. However, as
she follows the
path, she finds that it
leads her back to the house. When she tries to
speed up,
she not only returns to the
house, she crashes into it. Hence, forward
movement takes Alice back to her
starting point (Red Queen dynamics), and
rapid movement causes abrupt stops
(extinction).
Eventually, Alice finds
herself in a patch of very vocal and opinionated
flowers;
the rose is especially vocal.
The flowers tell Alice that someone like her (the
Red
Queen) often passes through, and
Alice decides to seek this person, mostly as
a way to escape more verbal abuse.
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When Alice spots the Red Queen, she
begins moving toward her. But, the Red
Queen quickly disappears from sight.
Alice decides to follow the advice of the
rose, and go the other way
(
Immediately she comes face-to-face
with the Red Queen (see Lythgoe and
Read 1998).
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The
Red Queen then leads Alice directly to the top of
the hill. Along the way, the Red
Queen
explains that hills can become valleys, which
confuses Alice. Already, in this
world,
straight can become curvy, and progress can be
made only by going the opposite
direction; now, according to the Red
Queen, hills can become valleys and valleys can
become hills.
At the top of
the hill, the Red Queen begins to run, faster and
faster. Alice runs after the
Red Queen,
but is further perplexed to find that neither one
seems to be moving. When
they stop
running, they are in exactly the same place. Alice
remarks on this, to which
the Red Queen
responds:
keep in the same
place
required to stay in the same
place. Cessation of change may result in
extinction.
2
猎物
—
捕食者的简单模型
第三节
捕食模型
一、
Lotka-
Volterra
的捕食模型
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该模型是描述两个世代相重叠的不
同种群共存，假定没有其他限制因子，仅仅
由于捕食和被捕食的相互影响，导致种群密度
产生相应的变化。
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被捕食者种群：假如没有捕食者种群存在，被捕食者种群将以指数式增长：
式中，
N
为被捕食者密度，
r1
为被捕食者在没
有捕食者时的瞬时增长率。
但如果有捕食者种群共存，
被捕食者种群的增长模型就应加入被捕
食的影响因素：
其中<
/p>
P
为捕食者种群的密度，
ε
为捕食压力。
当
ε
为
0
时，
即没有
捕
食压力，增长模型就回到指数式增长方程；
ε
越大，表示捕食压
力越大，被捕食者种群的密度就越低。
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捕食者种群：假如没有被捕食者种群存在，捕食者种群密度将呈几
何
级数减少，数学表达式为：
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式中
p<
/p>
为捕食者种群密度，
r2
为捕食者种群在
没有被捕食者时的瞬时
死亡率。
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但如果有被捕食者种群共存，捕食
者种群的密度就会随被捕食者种
群密度的改变而改变，上述方程就应改写为：