Males and females flare or puff out their gill covers (opercula) to appear more impressive, either to intimidate other rivals or as an act of courtship. Other reasons for flaring can include when they are intimidated by movement or change of scene in their environments. Both sexes display pale horizontal bars if stressed or frightened. However, such colour changes, common in females of any age, are rare in mature males due to their intensity of colour. Females often flare at other females, especially when setting up a pecking order. Flirting fish behave similarly, with vertical instead of horizontal stripes indicating a willingness and readiness to breed (females only). Betta splendens enjoy a decorated tank, being a territorial fish it is necessary to establish territory even when housed alone. They may set up a territory centered on a plant or rocky alcove, sometimes becoming highly possessive of it and aggressive toward trespassing rivals. This is the reason why when kept with other fish the minimum tank size should be 45 litres (about 10 gallons). Contrary to popular belief, bettas are compatible with many other species of aquarium fish. Given the proper parameters bettas will be known to only be aggressive towards smaller and slower fish than themselves such as guppies.

do betta fish only fight other betta fish?

A: no

Although human eyes lack a tapetum lucidum, they still exhibit a weak reflection from the fundus, as can be seen in photography with the red-eye effect and with near-infrared eyeshine. Another effect in humans and other animals that may resemble eyeshine is leukocoria, which is a white shine indicative of abnormalities such as cataracts and cancers.

can human eyes reflect light in the dark?

A: yes

Generally, a passenger with an electronic ticket will only need a boarding pass. If a passenger has a paper airline ticket, that ticket (or flight coupon) may be required to be attached to the boarding pass for him or her to board the aircraft. For ''connecting flights'', a boarding pass is required for each new leg (distinguished by a different flight number), regardless of whether a different aircraft is boarded or not.

are tickets and boarding passes the same thing?

A: no

In the United States, certificates issued to the general public for deaths after 1990 may in some states be redacted to erase the specific cause of death (in cases where death was from natural causes) to comply with HIV confidentiality rules. In New York State, for instance, the cause of death on a general death certificate is only specified if death was accidental, homicide, suicide, or declared in absentia; all other deaths are only referred to as natural. All states have provisions, however, whereby immediate family members, law enforcement agencies, and governmental authorities (such as occupational health and safety groups) are able to obtain death certificates containing the full cause of death, even in cases of natural death.

does a death certificate have to show cause of death?

A:
no