DIVE DRY WITH DR. BILL #788: GO CRIMSON!
Now I'm no judge of fine art, but in my not-so-humble opinion two of the most beautiful fish in our waters are the baby garibaldi and the blue-banded goby (Lythrypnus dalli). Both are small but hard to overlook due to their brilliant blue and orange to red-orange coloration. Due to their size, underwater imagers must get up close and personal to get a good picture. Today I'll "focus" on the goby.
The goby family (Gobiidae) consists of some 1,951 species per Dr. Milton Love... imagine having to buy Christmas gifts for each member! They are a nearshore group, preferring inshore shallower waters to the unknown depths of Mother Ocean, although they may be seen at depths up to 250 feet. I'm a fairly shallow fellow myself and avoid depths greater than 200 feet.
The blue-banded or Catalina goby reaches a maximum length of about three inches. Milton refers to them as crimson with blue bands. I'm somewhat color blind and see them as reddish orange, but I like Milton's choice since I root for the Crimson each weekend during football season (and the Harvard-Yale game is upon us this weekend). Fortunately that color dominates over the Yale blue on these fish.
This species is known from Morro Bay in the north, the Gulf of California (Sea of Cortez) and south to Peru. However they are not common north of Pt. Conception. During the day you can often see them out in the open with nary a care in the world. Most predators would only consider them an hors d'oeuvre and not worthy of the expenditure of energy to capture them. However, at night when the ghouls and monsters come out, these fish seek shelter in nooks and crannies. They are often seen under the protective spines of sea urchins.
If you spend time watching these fish, you will frequently see them dart up from their perch into the water column to snatch a tasty morsel. My eyes aren't good enough to see what they're chowing down on. However Dr. Love suggests zooplankton for most while others prefer small bottom-dwelling invertebrates including crusty crustaceans, snails, bivalves and worms. He also states these tiny fish have been observed cleaning giant sea bass! In turn they are eaten by kelp bass, rockfish and others.
The blue-banded goby has a brief existence on Planet Ocean, rarely surviving 20 months. Due to this short lifespan, reproduction is critical for the continuation of the species in its given habitat. These fish are quite precocious, reaching sexual maturity at the tender age of a month after settling out of the plankton! In our waters these fish spawn winter, spring and summer (apparently taking a break in the fall although some may spawn year-round). Females may produce over 2,000 eggs although I have no clue how they can fit so many into their tiny bodies. These hatch out as planktonic larvae, drifting in the currents for a few months to see the world.
Those who think gender is fixed at birth don't know very much about biology. Those of us who do, know that fish like sheephead can begin life as one gender and switch to the other. Blue-banded gobies do that one better... they can switch back and forth or even have both sex organs at once! Males generally tend a small harem of females and are territorial. If the dominant male disappears, a female may change gender and replace him. Some of the males are sneaky and enter into the dominant male's territory and fertilize a few eggs.
Given the short life span, recruitment (or the arrival of new fish on a reef) is critical in maintaining the local population. Some years it is very light while during others it may be quite heavy. I have witnessed years in which the tiny young fish pepper the reef and are detectable primarily due to their bright color since they are often too small for my aging eyes to see clearly. I hope you have prescription lenses in your mask!
© 2018 Dr. Bill Bushing. For the entire archived set of over 750 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Blue-banded gobies perched in the dive park; leaping up to grab food particles and hiding under the spines of a black sea urchin.
Now I'm no judge of fine art, but in my not-so-humble opinion two of the most beautiful fish in our waters are the baby garibaldi and the blue-banded goby (Lythrypnus dalli). Both are small but hard to overlook due to their brilliant blue and orange to red-orange coloration. Due to their size, underwater imagers must get up close and personal to get a good picture. Today I'll "focus" on the goby.
The goby family (Gobiidae) consists of some 1,951 species per Dr. Milton Love... imagine having to buy Christmas gifts for each member! They are a nearshore group, preferring inshore shallower waters to the unknown depths of Mother Ocean, although they may be seen at depths up to 250 feet. I'm a fairly shallow fellow myself and avoid depths greater than 200 feet.
The blue-banded or Catalina goby reaches a maximum length of about three inches. Milton refers to them as crimson with blue bands. I'm somewhat color blind and see them as reddish orange, but I like Milton's choice since I root for the Crimson each weekend during football season (and the Harvard-Yale game is upon us this weekend). Fortunately that color dominates over the Yale blue on these fish.
This species is known from Morro Bay in the north, the Gulf of California (Sea of Cortez) and south to Peru. However they are not common north of Pt. Conception. During the day you can often see them out in the open with nary a care in the world. Most predators would only consider them an hors d'oeuvre and not worthy of the expenditure of energy to capture them. However, at night when the ghouls and monsters come out, these fish seek shelter in nooks and crannies. They are often seen under the protective spines of sea urchins.
If you spend time watching these fish, you will frequently see them dart up from their perch into the water column to snatch a tasty morsel. My eyes aren't good enough to see what they're chowing down on. However Dr. Love suggests zooplankton for most while others prefer small bottom-dwelling invertebrates including crusty crustaceans, snails, bivalves and worms. He also states these tiny fish have been observed cleaning giant sea bass! In turn they are eaten by kelp bass, rockfish and others.
The blue-banded goby has a brief existence on Planet Ocean, rarely surviving 20 months. Due to this short lifespan, reproduction is critical for the continuation of the species in its given habitat. These fish are quite precocious, reaching sexual maturity at the tender age of a month after settling out of the plankton! In our waters these fish spawn winter, spring and summer (apparently taking a break in the fall although some may spawn year-round). Females may produce over 2,000 eggs although I have no clue how they can fit so many into their tiny bodies. These hatch out as planktonic larvae, drifting in the currents for a few months to see the world.
Those who think gender is fixed at birth don't know very much about biology. Those of us who do, know that fish like sheephead can begin life as one gender and switch to the other. Blue-banded gobies do that one better... they can switch back and forth or even have both sex organs at once! Males generally tend a small harem of females and are territorial. If the dominant male disappears, a female may change gender and replace him. Some of the males are sneaky and enter into the dominant male's territory and fertilize a few eggs.
Given the short life span, recruitment (or the arrival of new fish on a reef) is critical in maintaining the local population. Some years it is very light while during others it may be quite heavy. I have witnessed years in which the tiny young fish pepper the reef and are detectable primarily due to their bright color since they are often too small for my aging eyes to see clearly. I hope you have prescription lenses in your mask!
© 2018 Dr. Bill Bushing. For the entire archived set of over 750 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Blue-banded gobies perched in the dive park; leaping up to grab food particles and hiding under the spines of a black sea urchin.
